The oppidum (a Roman fortification situated on an elevated spot) was an enclosure with a perimeter of about 900m protected by walls made of large roughly quarried limestone blocks. According to Abbot Bruyère, parts of these walls still remain, particularly on the North side to the left of the present day main access road and on the South side overlooking the valley. The oppidum was an irregular convex polygon in shape, following the various fluctuations of the terrain at the top of the hill. A deep cistern carved into the rock, which is now enclosed within the buildings around the chapel of Our Lady of the Mines, could date from the same period as the construction of the oppidum.
NOTRE DAME DES MINES