 This is not exactly above board to go exploring in the catacombs under Paris. No, it's neither above ground nor above board. But this is urban exploration, which is one of the names it goes by. But there are lovely French names for it. The people who love going down into the catacombs are called cataphiles or cataphiles. And the police who specialize in policing this subculture are called cataphliques. And if you take music down there, you play it on your cataboom piano.