As it is full of cave-dwellings, the subsoil of Saumur and its surroundings is often called "Gruyere".
Coutures marks the West border of the Tufa region and therefore the limit of the Cave-dwellings.
Until the 19th Century, half the population of the Gennois was living in cave-dwellings. You can still see some picturesque "villages troglodytes", at La Garde and Montsabert (in Coutures), or at Avort (in Louerre).
Hiking through the Gennes district, you can find two types of cave-dwellings :