When in Rome—the city of St. Valentine himself—it’s hard to escape the hints of romance clinging to the air. The martyred third-century saint is practically synonymous with the subject, and the city doesn’t shy from showcasing its connection with him or its reputation as a lovers’ paradise befitting his namesake holiday. But hidden beneath the ancient city, millennia-old subterranean wonders unveil a different version of St. Valentine’s Rome, where the mysterious and macabre replace mushy, manufactured love.
Slip beneath the city, and you’ll descend into the realm of the buried and forgotten, all concealed beneath the historic buildings that dominate the surface. Rome’s famous, extravagant churches hide labyrinthine cities of the dead, crypts adorned with thousands of bones, and chandeliers made from human vertebrae. Grand pleasure palaces and grim prisons said to have housed Biblical figures lurk just out of superterranean sight, while clandestine temples, rare catacombs, and ancient engineering marvels wait to reveal their secrets. Explore these 10 dark pockets of the eternal city’s past—no valentines required.