Cataphiles are fans and explorers of the Paris Catacombs. These extensive underground voids are the excavations left by the mining of Paris Stone (an attractive limestone used in public buildings) and gypsum (used to make the quick-setting “Plaster of Paris”). The gypsum caves have a habit of falling-in, creating unexpected sinkholes that endanger life and property. To the cataphiles’ dismay, the authorities are planning to fill them in with concrete – where the roofs aren’t propped up by skulls.

The catacombs have been used for storage, brewing (which likes a constant ambient temperature), as subterranean charnel houses for the bones of some six million Parisians, and for irregular rave parties (Paris really does have an underground music scene).