The Largue has its source in Oberlarg in the Glaserberg at 500 m altitude, near the Swiss border, and flows into the Ill at the height of Illfurth after a distance of 46 km. In the 19th century, it provided the energy for 53 mills in 34 villages.
A few metres away is the Mannlefelsen rock shelter where all the prehistoric history of the Alsatian Jura is concentrated on 8 metres of stratigraphy. Beware, the site is private and visible only from the path.