The Grotte Saint-Marcel is a cave classified since 1934 for its speleothems and prehistoric deposits. It is located in Bidon, in the Ardèche, on the border with the Gard. It has a total development of more than 57 km, a small part of which is open to tourist visits. It has yielded Mousterian lithic remains.

The cave is home to several prehistoric deposits that have yielded several thousand Mousterian lithic tools.