Editing Tunnel (section)

== Examples==
{{Cleanup|section|reason=just a random list|date=December 2017}}

=== In history ===
{{See also|History of rapid transit}}
{{More citations needed section|date=March 2013}}
[[File:Dudley Canal Tunnel Southern Portal.jpg|thumb|right|Southern portal of the 1791 Dudley Canal tunnel in England]]
[[File:Entrance of the Railway at Edge Hill, from Bury's Liverpool and Manchester Railway, 1831 - artfinder 122456.jpg|right|thumb|[[Thomas Talbot Bury]]'s watercolour of the Liverpool Edge Hill tunnel portals]]
[[File:Start of Lime Street Tunnel Cutting.jpg|right|thumb|A short section remains of the 1832 Edge Hill to Lime Street tunnel in [[Liverpool]]. This and a short section of the original tunnel nearer to Lime Street are the oldest rail tunnels in the world still in active use.]]
[[File:Leaving Liverpool Lime St - geograph.org.uk - 747034.jpg|thumb|right|[[Liverpool Lime Street railway station|Liverpool Lime Street]] Approach. The original two-track tunnel was removed to create a deep cutting. Some of the road bridges seen across the cutting are solid rock and in effect are a series of short tunnels.]]
[[File:Edge Hill cutting.jpg|thumb|right|The three eastern portals of Liverpool Edge Hill tunnels, built into a hand-dug deep cutting. The left tunnel with tracks is the short 1846 second Crown Street Tunnel, still used for shunting. In the center, partially hidden by undergrowth, is the disused {{convert|2.03|km|mi|abbr=on}} 1829 [[Wapping Tunnel]]. On the right, hidden by undergrowth, is the disused original short 1829 Crown Street Tunnel.]]
[[File:Donner Pass Summit Tunnel West Portal.jpg|right|thumb|The 1,659-foot (506 m) [[Donner Pass]] Summit Tunnel (#6) was in service from 1868 to 1993.]]
<!-- [[File:Lehigh Tunnel.jpg|thumb|[[Lehigh Tunnel]], [[Pennsylvania]]]] not particularly notable?? -->
[[File:Sommeiller drill.jpg|thumb|A late 19th-century pneumatic rock-drilling machine, invented by [[Germain Sommeiller]] and used to drill the first large tunnels through the [[Alps]]]]
[[File:Small operational brick tunnel.JPG|thumb|Small operational brick tunnel in France]]

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     NOTE TO EDITORS: Sort entries by earliest known date of completion. List distances by kilometres first, using the template {{convert|0.00|km|mi|abbr=on}} 
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The history of ancient tunnels and tunneling in the world is reviewed in various sources which include many examples of these structures that were built for different purposes.<ref>Klaus Grewe, 1998, Licht am Ende des Tunnels – Planung und Trassierung im antiken Tunnelbau, Verlag Philipp von Zabern, Mainz am Rhein.</ref><ref>Siamak Hashemi, 2013, The Magnificence of Civilization in Depths of Ground (A Review of Underground Structures in Iran – Past to Present), Shadrang Printing and Publishing Co., Tehran.</ref> Some well known ancient and modern tunnels are briefly introduced below:

* The [[qanat]] or [[kareez]] of [[Persia]] are water management systems used to provide a reliable supply of water to human settlements or for irrigation in hot, arid and semi-arid climates. The deepest known qanat is in the Iranian city of [[Gonabad]], which after 2700 years, still provides drinking and agricultural water to nearly 40,000 people. Its main well depth is more than {{convert|360|m|ft|abbr=on}}, and its length is {{convert|45|km|mi|abbr=on}}.<ref>UNESCO World Heritage Centre – World Heritage List: Qanats of Gonabad, Date of Inscription 2007, Reference No. 5207, At: {{cite web|url=https://whc.unesco.org/fr/listesindicatives/5207 |title=Qanats of Gonabad – UNESCO World Heritage Centre |access-date=14 December 2013 |url-status=live |archive-url=https://web.archive.org/web/20160329120845/https://whc.unesco.org/fr/listesindicatives/5207 |archive-date=29 March 2016 }}</ref>
* The [[Siloam Tunnel]] was built before 701&nbsp;BC for a reliable supply of water, to withstand [[siege]] attacks.
* The [[Eupalinian aqueduct]] on the island of [[Samos Island|Samos]] ([[North Aegean]], Greece) was built in 520&nbsp;BC by the ancient Greek engineer [[Eupalinos]] of [[Megara]] under a contract with the local community. Eupalinos organised the work so that the tunnel was begun from both sides of Mount Kastro. The two teams advanced simultaneously and met in the middle with excellent accuracy, something that was extremely difficult in that time. The aqueduct was of utmost defensive importance, since it ran underground, and it was not easily found by an enemy who could otherwise cut off the water supply to [[Pythagoreion]], the ancient capital of [[Samos Island|Samos]]. The tunnel's existence was recorded by Herodotus (as was the mole and harbour, and the third wonder of the island, the great temple to Hera, thought by many to be the largest in the Greek world). The precise location of the tunnel was only re-established in the 19th century by German archaeologists. The tunnel proper is {{convert|1030|m|ft|long|abbr=on|adj=mid}} and visitors can still enter it.
* One of the first known drainage and sewage networks in form of [[Drainage tunnel|tunnels]] was constructed at Persepolis in Iran at the same time as the construction of its foundation in 518&nbsp;BC. In most places the network was dug in the sound rock of the mountain and then covered by large pieces of rock and stone followed by earth and piles of rubble to level the ground. During investigations and surveys, long sections of similar rock tunnels extending beneath the palace area were traced by Herzfeld and later by Schmidt and their archaeological teams.<ref>Schmidt, E.F., 1953, Persepolis I – Structures, Reliefs, Inscriptions; The University of Chicago Oriental Institute Publications, Volume LXVIII, The University of Chicago Press.</ref>
* The [[Via Flaminia]], an important [[Roman road]], penetrated the [[Furlo]] pass in the [[Apennines]] through a tunnel which emperor [[Vespasian]] had ordered built in 76–77&nbsp;AD. A modern road, the SS 3 Flaminia, still uses this tunnel, which had a precursor dating back to the 3rd century BC, remnants of this earlier tunnel (one of the first road tunnels) are also still visible.
* The world's oldest tunnel traversing under a water body is claimed<ref>Blogcu {{cite web|url=http://terelek.blogcu.com/terelek-kaya-tuneli/319497 |title=TERELEK KAYA TÜNELİ – terelek |work=Blogcu |access-date=17 July 2014 |url-status=live |archive-url=https://web.archive.org/web/20160327222549/http://terelek.blogcu.com/terelek-kaya-tuneli/319497 |archive-date=27 March 2016 }}</ref> to be the ''Terelek kaya tüneli'' under [[Kızıl River]], a little south of the towns of [[Boyabat]] and [[Durağan]] in [[Turkey]], just downstream from where [[Kizil River]] joins its tributary [[Gökırmak]]. The tunnel is presently under a narrow part of a lake formed by a dam some kilometres further downstream. Estimated to have been built more than 2000 years ago, possibly by the same civilization that also built the royal tombs in a rock face nearby, it is assumed to have had a defensive purpose.
* [[Sapperton Canal Tunnel]] on the [[Thames and Severn Canal]] in [[England]], dug through hills, which opened in 1789, was {{convert|3.5|km|mi|abbr=on}} long and allowed [[Barge|boat]] transport of [[coal]] and other goods. Above it the [[Sapperton railway tunnel|Sapperton Long Tunnel]] was constructed which carries the "Golden Valley" railway line between [[Swindon]] and [[Gloucester]].
* The 1791 [[Dudley Tunnel|Dudley canal tunnel]] is on the [[Dudley Canal]], in [[Dudley]], [[England]]. The tunnel is {{convert|1.83|mi|km|1|order=flip}} long. Closed in 1962 the tunnel was reopened in 1973. The series of tunnels was extended in 1984 and 1989.<ref>[http://www.dudleycanaltrust.org.uk/interactive-tour-map/ Map of Dudley Canals | Discover Black Country Canals] {{webarchive |url=https://web.archive.org/web/20150409192053/http://www.dudleycanaltrust.org.uk/interactive-tour-map/ |date=9 April 2015 }}</ref>
* [[Fritchley Tunnel]], constructed in 1793 in Derbyshire by the [[Butterley Company]] to transport limestone to its ironworks factory. The Butterley company engineered and built its own railway. A victim of the depression the company closed after 219 years in 2009. The tunnel is the world's oldest railway tunnel traversed by rail wagons. Gravity and horse haulage was utilised. The railway was converted to steam locomotion in 1813 using a [[Steam Horse locomotive]] engineered and built by the Butterley company, however reverted to horses. Steam trains used the tunnel continuously from the 1840s when the railway was converted to a narrow gauge. The line closed in 1933. In the Second World War, the tunnel was used as an air raid shelter. Sealed up in 1977 it was rediscovered in 2013 and inspected. The tunnel was resealed to preserved the construction as it was designated an ancient monument.<ref name=listedbuilding1422984>{{NHLE|num=1422984|desc=Fritchley Tunnel, Butterley Gangroad|access-date=19 March 2015}}</ref><ref name=BBC22342239>{{cite news|url=https://www.bbc.co.uk/news/uk-england-derbyshire-22342239|title=Archaeologists find 'world's oldest railway tunnel' in Derbyshire|date=1 May 2013|work=BBC News}}</ref>
* The 1794 [[Butterley Tunnel|Butterley canal tunnel]] canal tunnel is {{cvt|2819|m|mi|1}} in length on the [[Cromford Canal]] in [[Ripley, Derbyshire]], England. The tunnel was built simultaneously with the 1793 Fritchley railway tunnel. The tunnel partially collapsed in 1900 splitting the Cromford Canal, and has not been used since. The Friends of Cromford Canal, a group of volunteers, are working at fully restoring the Cromford Canal and the Butterley Tunnel.<ref>[http://www.cromfordcanal.info Friends of the Cromford Canal – HOME]{{webarchive|url=https://web.archive.org/web/20161023115647/http://www.cromfordcanal.info/ |date=23 October 2016 }}</ref>
* The 1796 Stoddart Tunnel in Chapel-en-le-Frith in [[Derbyshire]] is reputed to be the oldest rail tunnel in the world. The rail wagons were originally horse-drawn.
* [[Smuggling tunnel#Derby Tunnels|Derby Tunnels]] in [[Salem, Massachusetts]], were built in 1801 to smuggle imports affected by President [[Thomas Jefferson]]'s new customs duties. Jefferson had ordered local militias to help the Custom House in each port collect these dues, but the smugglers, led by Elias Derby, hired the Salem militia to dig the tunnels and hide the spoil.
* A tunnel was created for the first true steam locomotive, from [[Penydarren]] to [[Abercynon]]. The Penydarren locomotive was built by [[Richard Trevithick]]. The locomotive made the historic journey from Penydarren to Abercynon in 1804. Part of this tunnel can still be seen at [[Pentrebach]], [[Merthyr Tydfil]], [[Wales]]. This is arguably the oldest railway tunnel in the world, dedicated only to self-propelled steam engines on rails.
* The [[Montgomery Bell Tunnel]] in Tennessee, an {{convert|88|m|ft|abbr=on|adj=mid|long}} water diversion tunnel, {{convert|4.50|x|2.45|m|ft|adj=mid|high|abbr=on}}, to power a water wheel, was built by slave labour in 1819, being the first full-scale tunnel in North America.
* Bourne's Tunnel, [[Rainhill]], near [[Liverpool]], England. It is {{convert|0.0321|km|m ft|abbr=on|order=out}} long. Built in the late 1820s, the exact date is unknown, however probably built in 1828 or 1829. This is the first tunnel in the world constructed under a railway line. The construction of the Liverpool to Manchester Railway ran over a horse-drawn tramway that ran from the Sutton collieries to the Liverpool-Warrington turnpike road. A tunnel was bored under the railway for the tramway. As the railway was being constructed the tunnel was made operational, opening prior to the Liverpool tunnels on the Liverpool to Manchester line. The tunnel was made redundant in 1844 when the tramway was dismantled.<ref>{{cite web|url=http://www.britishlistedbuildings.co.uk/en-507533-bourne-s-tunnel-at-sj5033491804-|title=Bourne's Tunnel at Sj5033491804 – Saint Helens – St Helens – England|work=British Listed Buildings|access-date=30 September 2014}}</ref>
* [[Crown Street railway station|Crown Street station]], [[Liverpool]], England, 1829. Built by [[George Stephenson]], a single track railway tunnel {{convert|266|m|ft|adj=mid|long|abbr=on}}, was bored from Edge Hill to Crown Street to serve the world's first intercity passenger railway terminus station. The station was abandoned in 1836 being too far from Liverpool city centre, with the area converted for freight use. Closed down in 1972, the tunnel is disused. However it is the oldest passenger rail tunnel running under streets in the world.<ref>{{cite web |url=http://www.liverpoolwiki.org/Liverpool%27s_Historic_Rail_Tunnels |archive-url=https://web.archive.org/web/20090517123220/http://www.liverpoolwiki.org/Liverpool%27s_Historic_Rail_Tunnels |url-status=dead |archive-date=17 May 2009 |title=Liverpool's Historic Rail Tunnels |publisher=The Liverpool Wiki |date=22 February 1999 |access-date=19 April 2013 }}</ref><ref name="subbrit.org.uk">{{cite web|url=http://www.subbrit.org.uk/sb-sites/sites/l/liverpool_edge_hill_cutting/index3.shtml|title=Subterranea Britannica: Sites|access-date=30 September 2014}}</ref>
* The 1829 [[Wapping Tunnel]] in Liverpool, England, at {{convert|2.03|km|mi|abbr=on}} long on a twin track railway, was the first rail tunnel bored under a metropolis. The tunnel's path is from Edge Hill in the east of the city to [[Wapping Dock]] in the south end Liverpool docks. The tunnel was used only for freight terminating at the [[Park Lane railway goods station|Park Lane goods terminal]]. Currently disused since 1972, the tunnel was to be a part of the [[Merseyrail]] metro network, with work started and abandoned because of costs. The tunnel is in excellent condition and is still being considered for reuse by Merseyrail, maybe with an underground station cut into the tunnel for Liverpool university. The river portal is opposite the new [[Echo Arena Liverpool|King's Dock Liverpool Arena]] being an ideal location for a serving station. If reused the tunnel will be the oldest used underground rail tunnel in the world and oldest section of any underground metro system.<ref name="subbrit.org.uk"/><ref>{{cite web|url=http://www.forgottenrelics.co.uk/tunnels/gallery/wapping.html|title=Wapping Tunnel|access-date=30 September 2014}}</ref><ref name="maund">{{cite book |title= Merseyrail electrics: the inside story |author=Maund, T.B. |publisher= NBC Books |year=2001 |location=Sheffield |oclc=655126526}}</ref>
* 1832, [[Liverpool Lime Street railway station|Lime Street railway station]] tunnel, Liverpool. A two track rail tunnel, {{convert|1.811|km|mi|abbr=on}} long was bored under the metropolis from Edge Hill in the east of the city to Lime Street in Liverpool's city centre. The tunnel was in use from 1832 being used to transport building materials to the new Lime St station while under construction. The station and tunnel was opened to passengers in 1836. In the 1880s the tunnel was converted to a deep cutting, open to the atmosphere, being four tracks wide. This is the only occurrence of a major tunnel being removed. Two short sections of the original tunnel still exist at Edge Hill station and further towards Lime Street, giving the two tunnels the distinction of being the oldest rail tunnels in the world still in use, and the oldest in use under streets.<ref>[http://www.hows.org.uk/personal/rail/incline/lls.htm Liverpool Lime St] {{webarchive |url=https://web.archive.org/web/20160304031133/http://www.hows.org.uk/personal/rail/incline/lls.htm |date=4 March 2016 }}</ref> Over time a {{convert|525|m|mi|abbr=on}} section of the deep cutting has been converted back into tunnel due to sections having buildings built over. 
* [[Box Tunnel]] in England, which opened in 1841, was the longest railway tunnel in the world at the time of construction. It was dug by hand, and has a length of {{convert|2.9|km|mi|abbr=on}}.
* The {{convert|1.1|km|mi|abbr=on}} 1842 Prince of Wales Tunnel, in [[Shildon]] near Darlington, England, is the oldest sizeable tunnel in the world still in use under a settlement.
* The [[Victoria Tunnel (Newcastle)|Victoria Tunnel Newcastle]] opened in 1842, is a {{convert|2.4|mi|km|order=flip|adj=on}} subterranean wagonway with a maximum depth of {{convert|85|ft|0|order=flip}} that drops {{convert|222|ft|0}} from entrance to exit. The tunnel runs under Newcastle upon Tyne, England, and originally exited at the River Tyne. It remains largely intact. Originally designed to carry coal from [[Spital Tongues]] to the river, in WW2 part of the tunnel was used as a shelter. Under the management of a charitable foundation called the Ouseburn Trust it is currently used for heritage tours.
* The [[Thames Tunnel]], built by [[Marc Isambard Brunel]] and his son [[Isambard Kingdom Brunel]] opened in 1843, was the first tunnel (after Terelek) traversing under a water body, and the first to be built using a [[tunnelling shield]]. Originally used as a foot-tunnel, the tunnel was converted to a railway tunnel in 1869 and was a part of the [[East London Line]] of the [[London Underground]] until 2007. It was the oldest section of the network, although not the oldest purpose built rail section. From 2010 the tunnel became a part of the [[London Overground]] network.
* The {{convert|3.34|km|mi|abbr=on}} [[Victoria Tunnel (Liverpool)|Victoria Tunnel]]/[[Waterloo Tunnel]] in [[Liverpool]], England, was bored under a metropolis opening in 1848. The tunnel was initially used only for rail freight serving the Waterloo Freight terminal, and later freight and passengers serving the [[Liverpool Riverside railway station|Liverpool ship liner terminal]]. The tunnel's path is from Edge Hill in the east of the city to the north end Liverpool docks at [[Waterloo Dock (Liverpool)|Waterloo Dock]]. The tunnel is split into two tunnels with a short open air cutting linking the two. The cutting is where the cable hauled trains from Edge Hill were hitched and unhitched. The two tunnels are effectively one on the same centre line and are regarded as one. However, as initially the {{convert|2375|m|mi|abbr=on}} long Victoria section was originally cable hauled and the shorter {{convert|862|m|yd|abbr=on}} Waterloo section was locomotive hauled, two separate names were given, the short section was named the [[Waterloo Tunnel]]. In 1895 the two tunnels were converted to locomotive haulage. Used until 1972, the tunnel is still in excellent condition. A short section of the Victoria tunnel at Edge Hill is still used for shunting trains. The tunnel is being considered for reuse by the [[Merseyrail]] network. Stations cut into the tunnel are being considered and also reuse by a monorail system from the proposed [[Liverpool Waters]] redevelopment of Liverpool's Central Docks has been proposed.<ref>{{cite web|url=http://www.forgottenrelics.co.uk/tunnels/gallery/victoria.html|title=Victoria Tunnel|access-date=30 September 2014}}</ref><ref>{{cite web|url=http://www.forgottenrelics.co.uk/tunnels/gallery/waterloo.html|title=Waterloo Tunnel|access-date=30 September 2014}}</ref>
* The summit tunnel of the [[Semmering railway]], the first Alpine tunnel, was opened in 1848 and was {{convert|1.431|km|mi|abbr=on}} long. It connected rail traffic between [[Vienna]], the capital of [[Austro-Hungarian Empire]], and [[Trieste]], its port.
* The [[Giovi Rail Tunnel]] through the [[Appennini]] Mounts opened in 1854, linking the capital city of the [[Kingdom of Sardinia]], [[Turin]], to its port, [[Genoa]]. The tunnel was {{convert|3.25|km|mi|abbr=on}} long.
* The oldest underground sections of the [[London Underground]] were built using the cut-and-cover method in the 1860s, and opened in January 1863. What are now the [[Metropolitan line|Metropolitan]], Hammersmith & City and Circle lines were the first to prove the success of a [[rapid transit|metro]] or subway system.
*On 18 June 1868, the [[Central Pacific Railroad]]'s {{convert|1,659|ft|m|order=flip|adj=on}} Summit Tunnel (Tunnel #6) at [[Donner Pass]] in the California [[Sierra Nevada (U.S.)|Sierra Nevada]] mountains was opened, permitting the establishment of the commercial mass transportation of passengers and freight over the Sierras for the first time. It remained in daily use until 1993, when the [[Southern Pacific Railroad]] closed it and transferred all rail traffic through the {{convert|10322|ft|m|adj=on|order=flip}} long Tunnel #41 (a.k.a. "The Big Hole") built a mile to the south in 1925.
* In 1870, after fourteen years of works, the [[Fréjus Rail Tunnel]] was completed between France and Italy, being the second-oldest Alpine tunnel, {{convert|13.7|km|mi|abbr=on}} long. At that time it was the longest in the world.
* The third Alpine tunnel, the [[Gotthard Rail Tunnel]], between northern and southern Switzerland, opened in 1882 and was the longest rail tunnel in the world, measuring {{convert|15|km|mi|abbr=on}}.
* The 1882 [[Col de Tende Road Tunnel]], at {{convert|3.182|km|mi|abbr=on}} long, was one of the first long road tunnels under a pass, running between France and Italy.
* The [[Mersey Railway]] tunnel opened in 1886, running from Liverpool to Birkenhead under the River Mersey. The [[Mersey Railway]] was the world's first deep-level underground railway. By 1892 the extensions on land from Birkenhead Park station to Liverpool Central Low level station gave a tunnel {{convert|3.12|mi|km|abbr=on|order=flip}} in length. The under river section is {{convert|0.75|mi|km|abbr=on|order=flip}} in length, and was the longest underwater tunnel in world in January 1886.<ref>{{cite web|url=http://www.upton-wirral.co.uk/wir2.php|title=Mersey Railway Tunnel|access-date=30 September 2014|url-status=dead|archive-url=https://web.archive.org/web/20130529074903/http://www.upton-wirral.co.uk/wir2.php|archive-date=29 May 2013}}</ref><ref>[http://www.engineering-timelines.com/scripts/engineeringItem.asp?id=1151 Engineering Timelines – Mersey Railway] {{webarchive |url=https://web.archive.org/web/20120322113859/http://www.engineering-timelines.com/scripts/engineeringItem.asp?id=1151 |date=22 March 2012 }}</ref>
* The rail [[Severn Tunnel]] was opened in late 1886, at {{convert|7.008|km|mi|abbr=on}} long, although only {{convert|3.62|km|mi|abbr=on}} of the tunnel is actually under the River Severn. The tunnel replaced the Mersey Railway tunnel's longest under water record, which was held for less than a year.
* [[James Greathead]], in constructing the City & South London Railway tunnel beneath the Thames, opened in 1890, brought together three key elements of tunnel construction under water: 
*#shield method of excavation; 
*#permanent cast iron tunnel lining; 
*#construction in a compressed air environment to inhibit water flowing through soft ground material into the tunnel heading.<ref name="nrhp_stclair"/>
* Built in sections between 1890 and 1939, the section of London Underground's [[Northern line]] from Morden to East Finchley via Bank was the longest railway tunnel in the world at {{convert|27.8|km|mi|abbr=on}} in length.
* [[St. Clair Tunnel]], also opened later in 1890, linked the elements of the Greathead tunnels on a larger scale.<ref name="nrhp_stclair">{{Cite web |last=Lange |first=Robie S. |date=February 1993 |title=National Register of Historic Places Inventory-Nomination: St. Clair River Tunnel / St. Clair Railroad Tunnel |url={{NHLS url|id=70000684}} |access-date=2024-01-23 |website=National Park Service}}</ref>
* In 1906 the fourth Alpine tunnel opened, the [[Simplon Tunnel]], between Switzerland and Italy. It is {{convert|19.8|km|mi|abbr=on}} long, and was the longest tunnel in the world until 1982. It was also the deepest tunnel in the world, with a maximum rock overlay of approximately {{convert|2150|m|abbr=on}}.
* The 1927 [[Holland Tunnel]] was the first underwater tunnel designed for automobiles. The construction required a novel [[Holland Tunnel#Ventilation system|ventilation system]].
* In 1945 the [[Delaware Aqueduct]] tunnel was completed, supplying water to New York City. At {{convert|137|km|mi|abbr=on}} it is the longest tunnel in the world.
* In 1988 the {{convert|53.850|km|mi|abbr=on}} long [[Seikan Tunnel]] in Japan was completed under the [[Tsugaru Strait]], linking the islands of [[Honshu]] and [[Hokkaido]]. It was the longest railway tunnel in the world at that time.
* [[Ryfast]] is the longest undersea road tunnel. It is {{cvt|14.3|km|mi}} in length.<ref>{{cite web|url=https://www.tu.no/artikler/i-dag-sprenges-siste-fjellrest-vekk-i-verdens-lengste-undersjoiske-veitunnel/410538|title=Nå er siste fjellrest sprengt vekk i verdens lengste undersjøiske veitunnel|date=26 October 2017}}</ref> The tunnel opened for use in 2020.

=== Longest ===
{{Main|List of longest tunnels}}
[[File:Gotthard Base Tunnel.jpg|thumb|The Gotthard Base Tunnel is the first flat route through a major mountain range.]]
* The [[Thirlmere Aqueduct]] in [[North West England]], United Kingdom is sometimes considered the longest tunnel, of any type, in the world at {{convert|154|km|mi|abbr=on}}, though the aqueduct's tunnel section is not continuous.{{dubious|date=March 2014}}
* The [[Dahuofang Water Tunnel]] in [[China]], opened in 2009, is the third longest water tunnel in the world at {{cvt|85.3|km}} length. 
* The [[Gotthard Base Tunnel]] in [[Switzerland]], opened in 2016, is the longest and deepest railway tunnel in the world at {{cvt|57.1|km}} length and {{cvt|2450|m}} maximum depth below the [[Saint-Gotthard Massif|Gotthard Massif]]. It provides a [[NRLA|flat transit route]] between the North and South of Europe under the [[Swiss Alps]], at a maximum elevation of {{cvt|549|m}}. 
* The [[Seikan Tunnel]] in [[Japan]] connects the main island of [[Honshu]] with the northern island of [[Hokkaido]] by rail. It is {{convert|53.9|km|adj=on}} long, of which {{cvt|23.3|km}} are crossing the [[Tsugaru Strait]] undersea.
* The [[Channel Tunnel]] crosses the [[English Channel]] between [[France]] and the [[United Kingdom]]. It has a total length of {{cvt|50|km}}, of which {{cvt|39|km}} are the world's longest undersea tunnel section.
* The [[Lötschberg Base Tunnel]] in [[Switzerland]] was the longest land rail tunnel, with a length of {{cvt|34.5|km}}, from its inauguration in 2007 until the completion of the [[Gotthard Base Tunnel]] in 2016.
* The [[Lærdal Tunnel]] in Norway from [[Lærdal]] to [[Aurland]] is the world's longest road tunnel, intended for cars and similar vehicles, at {{convert|24.5|km|mi|abbr=on}}.
* The [[Zhongnanshan Tunnel]] in [[People's Republic of China]] opened in January 2007 is the world's second longest [[highway]] tunnel and the longest mountain road tunnel in Asia, at {{convert|18|km|mi|abbr=on}}.
<!-- construction not even started*The [[Ryfast]] road program in [[Stavanger]], Norway, includes the tunnel [[Solbakktunnelen]], which is scheduled to be opened within 2015. This tunnel will be {{convert|14|km|mi|abbr=on}} long, making it both the world's longest underwater road tunnel and longest underwater highway tunnel. The tunnel will have four driving lanes in total, and a speed limit of {{convert|90|km/h|mph|abbr=on|lk=on}}. -->
* The longest canal tunnel is the [[Rove Tunnel]] in France, over {{convert|7.12|km|mi|abbr=on}} long.

=== Notable ===
<!-- NOTE TO EDITORS: Sort entries by earliest known or expected date of completion. List distances by kilometres first, using the template {{convert|0.00|km|mi|abbr=on}} -->
[[File:Tunnel-large.jpg|thumb|right|The [[Big Dig]] road vehicle tunnel in [[Boston]], U.S.]]
[[File:Gerrards Cross railway station 2.jpg|thumb|right|The [[Gerrards Cross tunnel]] in England, completed in 2010. Looking west towards the station in March 2005, showing the extent of construction three months before a small section collapsed.]]
[[File:Sideling Hill Tunnel 2009.jpg|thumb|right|The eastern portal of the abandoned [[Sideling Hill Tunnel]], Pennsylvania, U.S., in 2009]]
* The [[Moffat Tunnel]], opened in 1928, passes under the [[Continental Divide of the Americas]] in [[Colorado]]. The tunnel is {{convert|10.0|km|mi|abbr=on}} long and at an elevation of {{convert|2816|m|ft|abbr=on}} is the highest active railroad tunnel in the U.S. (The inactive [[Tennessee Pass Line]] and the historic [[Alpine Tunnel]] are higher.)
* [[Williamson's tunnels]] in [[Liverpool]], from 1804 and completed around 1840 by a wealthy eccentric, are probably the largest underground [[folly]] in the world. The tunnels were built with no functional purpose. 
* The [[Chicago Tunnel Company|Chicago freight tunnel network]] is the largest urban street tunnel network, comprising {{convert|97|km|mi|abbr=on}} of tunnels beneath the majority of downtown [[Chicago]] streets. It operated between 1906 and 1956 as a freight network, connecting building basements and railway stations. Following a [[Chicago flood|1992 flood]] the network was sealed, although some parts still carry utility and communications infrastructure.
* The [[Pennsylvania Turnpike]] opened in 1940 with seven tunnels, most of which were bored as part of the stillborn [[South Pennsylvania Railroad]] and giving the highway the nickname "Tunnel Highway". Four of the tunnels ([[Allegheny Mountain Tunnel|Allegheny Mountain]], [[Tuscarora Mountain Tunnel|Tuscarora Mountain]], [[Kittatinny Mountain Tunnel|Kittatinny Mountain]], and [[Blue Mountain Tunnel|Blue Mountain]]) remain in active use, while the other three ([[Laurel Hill Tunnel|Laurel Hill]], [[Rays Hill Tunnel|Rays Hill]], and [[Sideling Hill Tunnel|Sideling Hill]]) were bypassed in the 1960s; the latter two tunnels are on a bypassed section of the Turnpike now commonly known as the [[Abandoned Pennsylvania Turnpike]].
* The [[Essingeleden|Fredhälls road tunnel]] was opened in 1966, in [[Stockholm, Sweden]], and the [[Elbe Tunnel (1975)|New Elbe road tunnel]] opened in 1975 in [[Hamburg, Germany]]. Both tunnels handle around 150,000 vehicles a day, making them two of the most trafficked tunnels in the world.
* The [[Honningsvåg Tunnel]] ({{convert|4.443|km|mi|abbr=on|sigfig=3}} long) opened in 1999 on [[European route E69]] in Norway as the world's northernmost road tunnel, except for mines (which exist on [[Svalbard]]).
* The Central Artery road tunnel in [[Boston, Massachusetts]], is a part of the larger [[Big Dig (Boston, Massachusetts)|Big Dig]] completed around 2007, and carries approximately 200,000 vehicles/day under the city along [[Interstate 93]], [[U.S. Route 1 in Massachusetts|US Route 1]], and [[Massachusetts Route 3]], which share a [[Concurrency (road)|concurrency]] through the tunnels. The Big Dig replaced Boston's old badly deteriorated I-93 elevated highway.
* The Stormwater Management And Road Tunnel or [[SMART Tunnel]], is a combined storm drainage and road structure opened in 2007 in [[Kuala Lumpur]], Malaysia. The {{convert|9.7|km|mi|abbr=on}} tunnel is the longest stormwater [[drainage tunnel]] in South East Asia and second longest in Asia. The facility can be operated as a simultaneous traffic and stormwater passage, or dedicated exclusively to stormwater when necessary.
* The [[Eiksund Tunnel]]<ref>{{Cite web |date=2008-03-02 |title=Safety: World's Deepest Subsea Tunnel Opens in Norway |url=http://www.tunnelintelligence.com/safety-in-detail-106.html |url-status=usurped |archive-url=https://web.archive.org/web/20120317104705/http://www.tunnelintelligence.com/safety-in-detail-106.html |archive-date=2012-03-17 |access-date=2024-01-23 |website=www.tunnelintelligence.com}}</ref> on national road Rv 653 in Norway is the world's deepest subsea road tunnel, measuring {{convert|7.776|km|mi|abbr=on}} long, with deepest point at {{convert|-287|m|ft|abbr=on}} below the sea level, opened in February 2008.
* [[Gerrards Cross Tunnel|Gerrards Cross railway tunnel]], in England, opened in 2010, is notable in that it converted an existing railway cutting into a tunnel to create ground to build a supermarket over the tunnel. The railway in the cutting was first opened around 1906, stretching over 104 years to complete a railway tunnel. The tunnel was built using the cover method with craned in prefabricated forms in order to keep the busy railway operating. A branch of the [[Tesco]] supermarket chain occupies the newly created ground above the railway tunnel, with an adjacent existing railway station at the end of the tunnel. During construction, a portion of the tunnel collapsed when soil cover was added. The prefabricated forms were covered with a layer of reinforced concrete after the collapse.<ref>{{cite web|url=http://www.nce.co.uk/news/transport/costain-finishes-gerrards-cross-tunnel-rebuild/5218141.article|title=Costain finishes Gerrards Cross tunnel rebuild|access-date=30 September 2014|date=19 May 2010}}</ref>
* The [[Fenghuoshan tunnel]], completed in 2005 on the [[Qinghai-Tibet railway]] is the world's highest railway tunnel, about {{convert|4.905|km|mi|abbr=on|sigfig=3}} above sea level and {{convert|1,338|m|mi|abbr=on|sigfig=3}} long.
* The [[La Línea (Road Pass)|La Linea]] Tunnel in [[Colombia]], 2016, is the longest, {{convert|8.58|km|mi|abbr=on|sigfig=3}}, mountain tunnel in South America. It crosses beneath a mountain at {{convert|2500|m|ft|abbr=on|sigfig=5}} <!-- needs clarification --> above sea level with six traffic lanes, and it has a parallel emergency tunnel. The tunnel is subject to serious [[groundwater]] pressure. The tunnel will link [[Bogotá]] and its urban area with the coffee-growing region, and with the main port on the Colombian Pacific coast.
* The [[Tunnel and Reservoir Plan|Chicago Deep Tunnel Project]] is a network of {{convert|175|km|mi|abbr=on}} of [[drainage tunnel]]s designed to reduce flooding in the [[Chicago metropolitan area|Chicago area]]. Started in the mid-1970s, the project is due to be completed in 2029.
* [[New York City Water Tunnel No. 3]], started in 1970, has an expected completion beyond 2026,<ref>{{Cite web |last=Kensinger |first=Nathan |date=22 April 2021 |title=NYC's Giant Water Tunnel Begins Work On Final Shafts, Following 50 Years Of Construction |url=https://gothamist.com/news/nycs-giant-water-tunnel-begins-work-on-final-shafts-following-50-years-of-construction |url-access=registration |access-date=15 September 2022 |website=Gothamist |language=en |quote=These last two shafts are now expected to be done by 2026, according to the DEP, but the tunnel still won't be complete. The original plans called for one more extension—a 14-mile conduit between Yonkers, the Bronx and Queens.}}</ref> and will measure more than {{convert|97|km|mi|abbr=on|adj=mid|long}}.<ref>{{cite web|url=http://www.nyc.gov/html/dep/html/news/3rdtunnel.html |archive-url=https://web.archive.org/web/20070621120811/http://www.nyc.gov/html/dep/html/news/3rdtunnel.html |archive-date=21 June 2007 |title=City Water Tunnel No. 3 |access-date=19 April 2013}}</ref>