Centuries ago, Paris ran out of space in its cemeteries and stored the bones of the dead in underground passageways. The passageways were originally carved to generate stone for buildings, and go for miles under the city. It is dark and damp in the Catacombs, but surprisingly not too moldy. Most significantly, you pass by the remains of hundreds of thousands in just a few of the chambers. The long bones are stacked very tightly, about 2 meters high and up to 30 meters deep into the rock. Skulls are often used decoratively. One can't help but focus on individuals and wonder about their fates, and then step back and appreciate the masses of people who had their moment in time.