1. Grotte Celestine Cave, Rauzan
These limestone caves run under the town of Rauzan and feature an underground river which has had many uses over the last two centuries.
They were first discovered by accident in 1845 and then forgotten about for many years before being opened to the public.
You can now take an tour along the caves, kitted out with torches, waterproofs and a helmet, and learn about the impressive rock formations.