Editing Lahn (section)

==Course==
The Lahn first flows in a northeasterly direction through the southeastern Rothaargebirge and its foothills. From about the [[Bad Laasphe]] community of Feudingen, it turns primarily to the east.

===Upper Lahntal and Wetschaft Depression===
[[File:Lahn Wetschaft.jpg|thumb|left|225px|The confluence of the Wetschaft with the Lahn]] [[File:Laasphe De Merian Hassiae 144.jpg|thumb|right|225px|The Upper Lahn Valley at [[Bad Laasphe]] from the ''[[Topographia Hassiae]]'' of [[Matthäus Merian the Younger|Matthäus Merian]], 1655]]The section of the Lahn below the town of Bad Laasphe is geographically known as the Upper Lahn Valley (German: Ober Lahntal). Above Bad Laasphe, where the river flows between the Rothaargebirge on the left (i.e. to the north) and the [[Gladenbach Uplands]] on the right, the Lahn Valley is simply considered part of these mountains.

Between Niederlaasphe (of Bad Laasphe) and Wallau (of [[Biedenkopf]]), the river crosses the border between North Rhine-Westphalia and Hesse. It then flows in an easterly direction through some districts of Biedenkopf (but not the central town) and the towns of [[Dautphetal]] and [[Lahntal]]. It is joined from the right by the [[Perf (Lahn)|Perf]] at Wallau and at Friedensdorf (of Dautphetal) by the [[Dautphe]] (which flows in a side valley to the south).

Shortly after the village of Caldern (of Lahn Valley), the ridgeline of the Rothaargebirge on the north ends with the Wollenberg and that of the Gladenbach Bergland with the Hungert. The Lahn leaves the [[Rhenish Slate Mountains]] for a long section and reaches the [[West Hesse Highlands]], where it flows through the extreme south of the [[Wetschaft Depression]], north of the Marburger Rücken. Where the [[Wetschaft]] flows into it from the Burgwald forest in the north (near the Lahntal village of Göttingen), the Lahn immediately changes direction by 90° to the right.

=== Marburg-Gießen Lahntal ===
The now southward-flowing Lahn then enters the Marburg-Gießen Lahntal. Shortly before [[Cölbe]], the [[Ohm (river)|Ohm]] enters from the left at the ''Lahn-Knie'' named area. Flowing from the [[Vogelsberg]] through the ''Ohmtal'', the Ohm is the Lahn's longest tributary, with a length of {{convert|59.7|km|mi}}.

The river then breaks through a [[sandstone]] [[mesa]] (the Marburger Rücken to the west and the Lahnberge to the east) into a valley which encompasses the entire territory of the city of [[Marburg]] and its suburbs. The valley begins after the river passes the Marburger Rücken near [[Weimar (Lahn)|Niederweimar]], where the [[Allna]] enters from the right. At the valley's southern end, the [[Zwesten Ohm]] enters from the Lahnberge. The right (western) side of the valley is again formed by the Gladenbacher Bergland, from which the [[Salzböde]] enters the Lahn. On the left rises the Lumda Plateau, from which the eponymous river [[Lumda (river)|Lumda]] flows into the Lahn near [[Lollar]]. Gradually the valley widens into the [[Gießen Basin]].

[[File:Heuchelheimer See.jpg|thumb|[[Heuchelheim Lake]]]]In [[Gießen]], after the inflow of the [[Wieseck (river)|Wieseck]] from the left, the Lahn's general direction of flow changes from the south to the west. The Gießen Basin extends a few more miles downstream to Atzbach, a suburb of [[Lahnau]]. From the 1960s until the 1980s, there was extensive [[gravel]] mining in this area. The area between [[Heuchelheim]], Lahnau, and the [[Wetzlar]] borough of Dutenhofen was to be completely mined and a water sports center with an Olympic-suitable [[rowing (sport)|rowing]] course built. This plan was partly realized, and the Heuchelheim Lake and Dutenhofen Lake are now popular recreational destinations for the surrounding region. Nature conservation organizations, however, were able to prevent further gravel mining, so the area is now one of the largest [[nature reserves]] in Hesse. Dutenhofen Lake marks Kilometer 0 of the Lahn as a federal waterway.

The Gießen Basin is surrounded by the mountain peaks of the Gleiberg, the Vetzberg, the Dünsberg, and the Schiffenberg.  At Wetzlar, the Lahn is joined by its second longest tributary, the [[Dill (river)|Dill]], which has a length of {{convert|55.0|km|mi}}. At this location, the valleys of the Lahn and Dill separate three parts of the Rhenish Slate Mountains from each other: the Gladenbach Bergland, the [[Westerwald]] to the northwest, and the [[Taunus]] to the south.

===Weilburg Lahntal===
[[File:Lahntunnel Weilburg.JPG|thumb|[[Weilburg]] boat tunnel]]After Wetzlar, the valley of the Lahn gradually narrows and at Leun enters the Weilburger Lahntal. The Weilburger Lahntal belongs to the larger Gießen-Koblenzer Lahntal physiographic province, considered part of the Rhenish Slate Mountains.

In the upper area of the Weilburg Lahntal (the Löhnberg Basin) are [[mineral springs]], such as the famous [[Selters (Lahn)|Selters]] mineral spring in the municipality of [[Löhnberg]]. In the lower area, where the river turns again to the south, the Lahn is entrenched canyon-like below the level of the surrounding geographic trough.

The city of [[Weilburg]] is wrapped by a marked loop of the river. The neck of this noose is traversed by a boat tunnel, unique in Germany. A little below Weilburg, the [[Weil (river)|Weil]], originating in the High Taunus, enters the Lahn.

===Limburger Basin===
At Aumenau in the municipality of [[Villmar]], the course of the Lahn reverses to the west again and enters the fertile Limburger Basin, where the river is incised to a depth of about {{convert|50|m|ft}}. Here the river is joined by two tributaries, the [[Emsbach]] coming from the Taunus and the [[Elbbach (Lahn)|Elbbach]] from the Westerwald. In this area are frequent outcroppings of [[Devonian]] [[limestone]], the so-called Lahn Marble (German: ''Lahnmarmor''), such as at [[Limburg an der Lahn]], where the [[Limburg Cathedral]] crowns such an outcropping. At Limburg, the river again enters a wider valley.

===Lower Lahntal===
Below [[Diez, Germany|Diez]], the Lahn absorbs the [[Aar (Lahn)|Aar]] from the south. At Fachingen in the municipality of [[Birlenbach]], it leaves the Limburger Basin and enters the Lower Lahntal.  Its course is incised over {{convert|200|m|ft}} deep in the Slate Mountains. Near [[Obernhof]], the [[Gelbach]] enters the Lahn opposite [[Arnstein Abbey]]. Then, after passing [[Nassau, Germany|Nassau]] and [[Bad Ems]], where, as in Fachingen, mineral springs (sources of Emser salt) can be found, it completes its {{convert|242|km|mi|abbr=on}} run, entering the Rhine in [[Lahnstein]], located five kilometers south of [[Koblenz]] at an elevation of {{convert|61|m|ft}}.

[[File:Lahnmundung.jpg|thumb|center|Confluence of the Lahn with the Rhine near Niederlahnstein (opposite [[Koblenz]]-Stolzenfels with Schloss Stolzenfels)|950px]]