Grotte Célestine, Underground cave system in Rauzan, France.

Grotte Célestine is an underground cave system with limestone passages containing stalactites, stalagmites, and mineral deposits throughout. An underground river flows through the passages and creates a wet environment with varied geological formations at different levels.

A seed merchant discovered the cave in 1845 while digging a well and uncovered the underground river system. Water had carved this passage through limestone over thousands of years before the discovery.

The cave is named after Célestine, a Rauzan resident who owned the land and for seven years let visitors pass through her bedroom to reach the shaft. Before 1930 it was called "grotte aux Torrents", and guided groups explored the underground riverbed by candlelight.

Visitors receive helmets, rubber boots, and headlamps for a guided tour lasting about one hour through the passages. It is wise to book ahead as places are limited and the temperature underground stays cool year-round.

The 13 m shaft that opened the cave in 1845 was a well dug for a grocer-seed merchant who wanted to draw water at his house; the well digger struck the cavity by chance. Visitors once entered through the bedroom of Célestine, the owner who let them pass for seven years.