This small church was constructed over the ruins of three temples dating to the Roman Republic.

Stone memorial that's said to predict the death of the pope and the site of the Cadaver Synod.

A fortified medieval basilica on the Caelian Hill preserves extraordinary frescoes and one of Rome's most beautiful hidden cloisters.

The best preserved Paleochristian basilica in Rome hides a number of oddities and secrets.

A Nesting Doll of Churches.

A rather vulgar example of the transition from Latin to the Italian vernacular.

A master of trompe-l'oeil creates a stunning, tourist-fooling dome out of a flat ceiling.

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

A freedman baker’s lavish tomb has a relief showing various stages of Roman bread making.

Believed to be the remains of the lost Temple of Minerva, this nymphaeum has been known by its misnomer to this day.

Ancient ruins hidden underneath a modern luxury hotel.

This ancient Roman arch misled treasure hunters for centuries.

This ancient market is often referred to as the oldest shopping mall in the world.

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

Inside this building is another country within Rome, a sovereign entity without a physical territory.

An 18th century fountain and two columns are all that remains of Rome's forgotten river harbor.

The spot where the fascist dictator made some of his most famous speeches including declaring war on Britain and France.

A rare example of a medieval house in Rome adorned with a melancholic inscription.

This curious, round temple is the oldest still-standing marble building in Rome.

The only remaining arch of the oldest stone bridge in Rome stands in the middle of the Tiber.

The "Great Sewer" of ancient Rome is one of the oldest sewer systems in the world, and is still in use.

The underground sanctuary of a mysterious ancient cult.

Installed in an act of one-upsmanship, the annual sundial in this church is also a symbolic victory for the Gregorian calendar.

This basilica is dedicated to two saints, one of which is known more for his famous quote.