The Lechfall is located on the southern edge of a short but deeply cut gorge, in which the Lech breaks through a rock barrier, which is attributed to the west of the Falkensteinkamm, east of the Ammergau Alps. This gorge (Latin Fauces: corridor, gullet) was named for feet. It originated at the end of the Würm ice age about 12,000 years ago, when the meltwater of the Lech glacier formed a large lake that extended to present day Pfronten. As an outflow of this lake, the Lech initially fell about 100 m deep over the rock ledge in the then Füssener Lake and then eroded the narrow canyon.