St. Paul's Catacombs: Underground City

Before cemeteries, we had catacombs. Miles of tunnels cut into the rock where Romans, Christians, and Jews buried their dead together.

It's cool, dark, and slightly spooky. You can walk through the tunnels and see the "Agape Tables" – round stone tables where families ate meals with their dead ancestors. (Yes, really).

It's a great escape from the summer heat. Down there, it's always a cool 18 degrees.