Craniums, femurs and fibula arranged on a wall in the Catacombs, a network of former limestone mines under place Denfert-Rochereau. Louis-Étienne Héricart de Thury, director of the Paris Mine Inspection Service, was the first to open the Catacombs to regular visits in July 1809 and renovated the necropolis with geometric alignments of the bones and skulls in 1811.