The Capuchin Crypt sets the tone for the tour. Capuchin monks used the bones of nearly 4,000 of their brothers to decorate this somber space in intricate floor-to-ceiling designs, earning it the macabre nickname of ‘the Bone Chapel’. Fewer visitors brave the Bone Chapel after dark, so you’ll have space to examine every detail of this strange place of worship, from an actual skull-and-crossbones to chandeliers made of human vertebrae. Your guide will tell you the theories, but it’s up to you to draw your own conclusions about the meaning of the crypt’s skeletal furnishings.

An air-conditioned coach will take you from here to your second site, the Catacombs of Priscilla. No other tour is permitted to enter these hallowed tunnels after-hours. Almost 2,000 years ago, early Christians took shelter here to bury their dead and practice their forbidden faith. With no other visitors around, and with your expert, English-speaking guide to relay the history of the tombs and tunnels, you can truly experience the atmosphere of this sacred spot. Follow the setting sun down into Rome’s mysterious underworld – and you’ll never see the city the same way again.