Tourniquet de Pierre Chave

The Tourniquet de Pierre Chave is a road bridge with an unusual looped structure that crosses the D49 road between Saint-Étienne de Crossey and Miribel-les-Échelles. The road passes underneath the bridge while simultaneously crossing over it, creating its distinctive double-crossing configuration.

Construction of this bridge dates to 1886 and connected the western Chartreuse region using innovative engineering methods of that era. The looped design was developed to overcome specific topographical challenges posed by the hillside terrain.

The bridge's location near the Rocharey State Forest provides access to the Chapel of Saint-Roch, built in 1631 as protection against the plague.

A dirt path within the bridge's loop provides parking space for visitors wanting to explore the surrounding hiking trails and forest areas. This location serves as a convenient starting point for walking routes through the natural landscape nearby.

The bridge employs a rare engineering solution where a single road both crosses over and passes under itself simultaneously, which was remarkably advanced for the 19th century. This double-crossing arrangement allowed the structure to navigate difficult terrain while maintaining direct connectivity between the two communities.