Editing Ancient Roman architecture (section)

== Infrastructure ==

=== Roads ===
{{Main|Roman road}}
[[File:Appia antica 2-7-05 048.jpg|thumb|The [[Appian Way]]]]
[[Roman road]]s were vital to the maintenance and development of the Roman state, and were built from about 500 BC through the expansion and consolidation of the [[Roman Republic]] and the [[Roman Empire]].{{sfn|Forbes|1993|page=146}} They provided efficient means for the overland movement of [[Military history of ancient Rome|armies]], officials and civilians, and the inland carriage of official communications and [[Roman commerce|trade]] goods.{{sfn|Kaszynski|2000|p=9}} At the peak of Rome's development, no fewer than 29 great military highways radiated from the capital, and the Late Empire's 113 provinces were interconnected by 372 great road links.{{sfn|Bunson|2009|p=195}}{{sfn|O'Flaherty|2002|p=2}}
Roman road builders aimed at a regulation width (see [[#Laws and standards|Laws and standards]] above), but actual widths have been measured at between {{convert|3.6|ft|m|abbr=on}} and more than {{convert|23|ft|m|abbr=on}}. Today, the concrete has worn from the spaces around the stones, giving the impression of a very bumpy road, but the original practice was to produce a surface that was much closer to being flat.

=== Aqueduct ===
{{Main|Roman aqueduct}}
{{further|List of aqueducts in the city of Rome|List of aqueducts in the Roman Empire}}
[[File:Pont_du_Gard_BLS.jpg|thumb|The [[Pont du Gard]], near [[Vers-Pont-du-Gard]], France]]
The [[Ancient Rome|Romans]] constructed numerous [[Aqueduct (bridge)|aqueducts]] in order to bring water from distant sources into their cities and towns, supplying [[Thermae|public baths]], [[latrine]]s, fountains and private households. Waste water was removed by complex [[Sanitation in ancient Rome|sewage systems]] and released into nearby bodies of water, keeping the towns clean and free from effluent. Aqueducts also provided water for mining operations, milling, farms and gardens.

Aqueducts moved water through gravity alone, being constructed along a slight downward gradient within conduits of stone, brick or concrete. Most were buried beneath the ground, and followed its contours; obstructing peaks were circumvented or, less often, tunnelled through. Where valleys or lowlands intervened, the conduit was carried on bridgework, or its contents fed into high-pressure lead, ceramic or stone pipes and siphoned across. Most aqueduct systems included sedimentation tanks, [[sluice]]s and distribution tanks to regulate the supply as needed.

Ancient Rome's first aqueduct – the [[Aqua Appia]] – supplied a water-fountain sited at the city's [[Forum Boarium|cattle market]] in the fourth century BC. By the third century AD, the city had [[List of aqueducts in the city of Rome|eleven aqueducts]], sustaining a population of over a million people in a water-extravagant economy; most of the water supplied the city's many public baths. Cities and municipalities throughout the Roman Empire emulated this model and funded aqueducts as objects of public interest and civic pride, "an expensive yet necessary luxury to which all could, and did, aspire."{{sfn|Gagarin|Fantham|2010|p= 145}}

Most Roman aqueducts proved reliable, and durable; some were maintained into the [[early modern]] era, and a few are still partly in use. Methods of aqueduct surveying and construction are noted by [[Vitruvius]] in his work ''[[De architectura]]'' (1st century BC). The general [[Frontinus]] gives more detail in his [[De aquaeductu|official report]] on the problems, uses and abuses of Imperial Rome's public water supply. Notable examples of aqueduct architecture include the supporting piers of the [[Aqueduct of Segovia]], and the aqueduct-fed cisterns of [[Constantinople]].

=== Bridges ===
{{Main|Roman bridge}}
{{further|List of Roman bridges}}
[[File:Roman_Bridge_of_Mérida_2023.jpg|thumb|[[Puente Romano, Mérida|Puente Romano]] over the Guadiana River at [[Mérida, Spain]]]]
Roman bridges, built by [[ancient Romans]], were the first large and lasting bridges built.{{sfn|O'Connor|1993|p=1}} Roman bridges were built with stone and had the [[arch]] as the basic structure. Most used [[Roman concrete|concrete]] as well, which the Romans were the first to use for bridges.

Roman arch bridges were usually [[semicircular]], although a few were [[circular segment|segmental]] (such as [[Alconétar Bridge]]). A segmental arch is an arch that is less than a semicircle.<ref>{{cite web|url=http://imgs.ebuild.com/woc/M880252.pdf |title=Designing the segmental arch |last=Beall |first=Christine |year=1988 |publisher=ebuild.com |access-date=8 May 2010}}</ref> The advantages of the segmental arch bridge were that it allowed great amounts of flood water to pass under it, which would prevent the bridge from being swept away during floods and the bridge itself could be more lightweight. Generally, Roman bridges featured wedge-shaped primary arch stones ([[voussoir]]s) of the same in size and shape. The Romans built both single spans and lengthy multiple arch [[Roman aqueducts|aqueducts]], such as the [[Pont du Gard]] and [[Segovia Aqueduct]]. Their bridges featured from an early time onwards flood openings in the piers, e.g. in the [[Pons Fabricius]] in Rome (62 BC), one of the world's oldest major bridges still standing. Roman engineers were the first and until the [[Industrial Revolution]] the only ones to construct bridges with [[Roman concrete|concrete]], which they called ''opus caementicium''. The outside was usually covered with brick or ashlar, as in the Alcántara bridge.

The Romans also introduced segmental arch bridges into bridge construction. The 330&nbsp;m long [[Limyra Bridge]] in southwestern [[Turkey]] features 26 segmental arches with an average span-to-rise ratio of 5.3:1,{{sfn|O'Connor|1993|p=126}} giving the bridge an unusually flat profile unsurpassed for more than a millennium. [[Trajan's bridge]] over the [[Danube]] featured open-spandrel segmental arches made of wood (standing on 40&nbsp;m high concrete piers). This was to be the longest arch bridge for a thousand years both in terms of overall and individual span length, while the longest extant Roman bridge is the 790&nbsp;m long [[Puente Romano]] at [[Mérida, Spain|Mérida]].

=== Canals ===
{{further|List of Roman canals}}
Roman canals were typically multi-purpose structures, intended for [[irrigation]], [[drainage]], [[land reclamation]], [[flood control]] and [[navigation]] where feasible. Some navigational canals were recorded by [[List of Graeco-Roman geographers|ancient geographers]] and are still traceable by [[modern archaeology]]. Channels which served the needs of urban [[water supply]] are covered at the [[List of aqueducts in the Roman Empire]].

=== Cisterns ===
{{further|List of Roman cisterns}}
[[File:Yerebatan2.JPG|thumb|The [[Basilica Cistern]] in [[Constantinople]] provided water for the [[Great Palace of Constantinople|Imperial Palace]].]]
Freshwater reservoirs were commonly set up at the termini of [[Roman aqueduct|aqueducts]] and their branch lines, supplying urban households, [[Villa rustica|agricultural estates]], imperial palaces, ''[[thermae]]'' or naval bases of the [[Roman navy]].{{sfn|Döring|2002|pp=310–319}}

=== Dams ===
{{further|List of Roman dams and reservoirs}}
Roman dam construction began in earnest in the [[History of the Roman Empire|early imperial period]].{{sfn|Hodge|1992|p=87}} For the most part, it concentrated on the semi-arid fringe of the empire, namely the provinces of [[Roman North Africa|North Africa]], the [[Near East]], and [[Hispania]].{{sfn|Schnitter|1978|p=28, fig. 7}}{{sfn|Hodge|1992|p=80}}{{sfn|Hodge|2000|p=332}} The relative abundance of Spanish dams below is due partly to more intensive field work there; for [[Roman Italy|Italy]] only the [[Subiaco Dams]], created by emperor [[Nero]] (54–68 AD) for recreational purposes, are attested.{{sfn|Smith|1970|pp=60f.}}{{sfn|Hodge|1992|p=87}} These dams are noteworthy, though, for their extraordinary height, which remained unsurpassed anywhere in the world until the [[Late Middle Ages]].{{sfn|Hodge|1992|p= 87}}

The most frequent dam types were earth- or rock-filled [[embankment dam]]s and masonry [[gravity dam]]s.{{sfn|Hodge|2000|pp=331f.}} These served a wide array of purposes, such as [[irrigation]], [[flood control]], river diversion, soil-retention, or a combination of these functions.{{sfn|Hodge|1992|pp=86f.}} The impermeability of Roman dams was increased by the introduction of waterproof hydraulic [[mortar (masonry)|mortar]] and especially ''[[opus caementicium]]'' in the [[Concrete Revolution]]. These materials also allowed for bigger structures to be built,{{sfn|Smith|1971|p=49}} like the [[Lake Homs Dam]], possibly the largest water barrier today,{{sfn|Smith|1971|p=42}} and the sturdy [[Harbaqa Dam]], both of which consist of a concrete core.

Roman builders were the first to realize the stabilizing effect of [[arch]]es and [[buttress]]es, which they integrated into their dam designs. Previously unknown dam types introduced by the Romans include [[arch-gravity dam]]s,{{sfn|Hodge|2000|p=332}}{{sfn|James|Chanson|2002}} [[arch dam]]s,{{sfn|Smith|1971|pp=33–35}}{{sfn|Schnitter|1978|pp=31f.}}{{sfn|Schnitter|1987a|p=12}}{{sfn|Schnitter|1987c|p=80}}{{sfn|Hodge|2000|p=332, fn. 2}} [[buttress dam]]s,{{sfn|Schnitter|1987b|pp=59–62}} and [[Arch dam#Variations|multiple-arch buttress dams]].{{sfn|Schnitter|1978|p=29}}{{sfn|Schnitter|1987b|pp=60, table 1, 62}}{{sfn|James|Chanson|2002}}{{sfn|Arenillas|Castillo|2003}}

===Defensive walls===
{{Main|Ancient Roman defensive walls}}
[[File:Lugo 2023 - Roman Walls.jpg|thumb|[[Roman walls of Lugo]], Spain]]
The Romans generally fortified cities rather than fortresses, but there are some fortified camps such as the [[Saxon Shore forts]] like [[Portus Adurni|Porchester Castle]] in England. City walls were already significant in [[Etruscan architecture]], and in the struggle for control of Italy under the early Republic many more were built, using different techniques. These included tightly fitting massive irregular polygonal blocks, shaped to fit exactly in a way reminiscent of later [[Inca]] work. The Romans called a simple rampart wall an [[Agger (ancient Rome)|agger]]; at this date great height was not necessary. The [[Servian Wall]] around Rome was an ambitious project of the early 4th century BC. The wall was up to {{convert|10|m|ft|abbr=off}} in height in places, {{convert|3.6|m|ft|abbr=off}} wide at its base, {{convert|11|km|mi|abbr=on}} long,<ref>Fields, Nic; Peter Dennis ''The Walls of Rome'' Osprey Publishing; 2008 {{ISBN|978-1-84603-198-4}} p.10 [https://books.google.com/books?id=SDxrLQymWWwC&dq=height+servian+wall&pg=PA10]{{Dead link|date=November 2023|bot=InternetArchiveBot|fix-attempted=yes}}</ref> and is believed to have had [[Servian Wall#Gates along the Servian Wall|16 main gates]], though many of these are mentioned only from writings, with no other known remains. Some of it had a ''fossa'' or ditch in front, and an agger behind, and it was enough to deter [[Hannibal]]. Later the [[Aurelian Wall]] replaced it, enclosing an expanded city, and using more sophisticated designs, with small forts at intervals.

The Romans walled major cities and towns in areas they saw as vulnerable, and parts of many walls remain incorporated in later defensive fortifications, as at [[Roman walls of Córdoba|Córdoba]] (2nd century BC), [[Chester city walls|Chester]] (earth and wood in the 70s AD, stone from {{Circa|100}}), and [[York city walls|York]] (from 70s AD). Strategic walls across open country were far rarer, and [[Hadrian's Wall]] (from 122) and the [[Antonine Wall]] (from 142, abandoned only 8 years after completion) are the most significant examples, both on the [[Picts|Pictish]] frontier of [[Roman Britain]].