The three levels of the cellars are well representative of the dug structures under the houses and illustrate the skillfulness of the builders in an especially difficult context.
We are not talking about strictly speaking troglodytism but about semi-troglodytism whose cellars of the Palais Saint Firmin are a remarkable example of harmony between buildings of stone and rock dug by man.
What emerges from this system of construction is the variaty of styles: the cellars have been built from the XIth century to the XVth century, moving from the Romanesque style to the Renaissance one. It is commonly thought that troglodytism means simplicity and bareness. In the cellars of the Palais Saint Firmin, you may doubt it when you see the abundance of their structures, of their vaults and the inventiveness of their construction works. The upper entangled structures as well as the vaults help identify the different eras. On the ground, rivulets and cisterns are dug into the rock.