This large, circular tomb is the final resting place of the first emperor of Rome.

This Roman arch marks the location of an ancient gate at one of the Seven Hills of Rome.

An abandoned Roman salami factory has found new life as an art space home to 200 squatters.

A hospital where antique dolls are given new life.

One of the most important yet well-hidden museums dedicated to the history of medicine.

A Nesting Doll of Churches.

The Pope’s secret escape route.

One of several skulls claiming to belong to the beheaded St. John the Baptist is on display at this Roman church.

The martyr's wax-enhanced skeletal remains lie preserved in a glass case in the Santa Maria della Vittoria in Rome.

A forgotten "city of water" underneath the famous Trevi district.

A collection of objects supposedly singed by the hands of souls in purgatory.

This ritzy Italian market is built around a statue of an unforgiven heretic who was burned for his belief in an endless universe.

A fairy tale castle in modern Rome.

Jesus' footprints and the first catacombs in the world.

This beautiful park on the outskirts of Rome protects the ruins of two colossal ancient aqueducts.

The engineering wonder and pleasure dome of a much-maligned emperor still holds undiscovered secrets.

The final resting place of the poets Shelley and Keats.

Architectural monsters are devouring this palace's every door and window.

2300-year-old Roman road connecting the empire.

The skull of the patron saint of lovers lies in the Basilica di Santa Maria in Cosmedin—maybe.

At the crypt of St. Mary of Eulogies and the Dead you are left alone to ponder mortality among piles of skulls.

The underground sanctuary of a mysterious ancient cult.

The only "Egyptian" pyramid in Europe and the legendary tomb of Remus.

The yawning maw of this pagan visage is said to bite off the hands of liars.