A beautiful gallery carved into the tuff of Clermont. Strata are clearly visible.

The frame of the Notre-Dame de l'Assomption de Clermont-Ferrand.

Underground Clermont-Ferrand are dug in the tuff. The tuff is consolidated volcanic ash, easy to dig. Sometimes you may discover metamorphic rock inside the tuff. This is this kind of rock you can see on the left of the photo. Useless and too heavy, it was left in the underground.

Notre-Dame de l'Assomption de Clermont-Ferrand is built of volcanic stone. That is why it is so dark in color.

The shape of the steps of the staircase is unique. It reduces the size of the staircase.

Surprisingly, the staircase is the center of the tower. Usually, the stairs are located at the ends or in small adjacent towers.

This underground labyrinth is located approximately 8 meters underground, which makes it ideal properties for the storage of wine.

The two stone rails were used to move easily wine barrels.