The most interesting feature of the Devil's Bridge Gorges - Gorges du Pont du Diable - is its unique configuration: the valley, which is very steep-sided even in Jotty, ends in a deep, narrow and - in places - underground fissure.This is where the Dranse de Morzine has met with the resistance of a limestone ridge, similar to those it has to cross further downstream, between La Vernaz and Pombourg or at the Bioge defile.

These repeated obstacles along the valley may be explained by the local geology: Cretaceous marls covering Jurassic limestone.These materials -originally marine sediments- underwent tremendous pressure from the Alps during their formation; pushed into folds one kilometer wide, they appear at intervals along the Dranse which has out through them in the wake of the glaciers. The valley broadens out with the softer marls; it narrows when crosing a limestone ridge, like here at the Devil's Bridge.