Creux Billard, Pit cave in Nans-sous-Sainte-Anne, France

Creux Billard is a circular collapse shaft about 60 metres wide and 90 metres deep in Nans-sous-Sainte-Anne, formed where the roof of a large underground chamber gave way. Its rim is broken into stepped ledges of pale grey and blue-grey rock, moss-covered and crossed by bare branches. A dark pool lies at the bottom, and a large porch 25 metres above the lake opens in the north wall.

In 1889, a tragic incident occurred when Miss Lachelier drowned in the chasm, and her body was recovered eight days later downstream. This discovery proved the water connection between the shaft and the Lison spring.

The name Creux Billard comes from the local word creux, a hollow, and the site has drawn visitors since at least the 19th century, when the Lachelier family came down into the shaft. Since 1912 the chasm has been listed by DREAL as a site of artistic character, together with the Lison spring and the Sarrazine cave.

The observation platform is reachable via a hiking trail starting from the Lison spring cascade, with stairs for easier access through the woodland path. The site is reasonably accessible if you use the provided steps and allow time for the walk.

During high water periods, two waterfalls flow simultaneously from the Château-Renaud stream, one emerging from the surface and another from a cave opening visible in the north wall. This rare sight reveals how water circulates through the underground system.