Fodor's Expert Review Les Catacombes

The catacombs are a fascinating haunt for anyone with morbid interests. A visit starts with a descent through dark, clammy passages that bring you to Paris's principal ossuary, which also once served as a hideout maze for the French Resistance. Bones from the defunct Cimetière des Innocents were the first to arrive in 1786, when decomposing bodies started seeping into the cellars of the market at Les Halles, drawing swarms of ravenous rats. The legions of bones were dumped here over the course of several decades by parish and by type—rows of skulls, packs of tibias, and piles of spinal disks, often rather artfully arranged. Among the nameless six million or so are the bones of Madame de Pompadour (1721–64), laid to rest with the riffraff after a lifetime spent as the mistress of Louis XV. One of the most interesting aspects of the catacombs is one you probably won't see: so-called cataphiles, or urban explorers, mostly art students, have found alternate entrances into the 300 km (186 miles) of tunnels and come to make art, party, and purportedly raise hell. Advance reservations are required (tickets are not refundable) and the line is always long to get in, as only 200 people can enter at a time. It's not recommended for claustrophobes or young children. Note that the exit and gift shop are at 21 bis avenue Rene Coty, about a half-mile from the entrance.