The catacombs of Paris are a fascinatingly morbid historic attraction, where you go deep underground to explore passageways of meticulously arranged bones and skulls. Somewhere between 6-7 million ...

The Catacombs of Paris hold many skeletons that are hidden 65 feet underground. NBC News’ Keir Simmons visits the Catacombs and talks to a historian about their history and significance.