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

This ancient Roman prison is decorated with an upside-down cross not as blasphemy but as saintly tribute.

Legend says this mysterious stone head belongs to a woman who was petrified by an alchemist.

Rome's first modern graffito is all that is left of a peaceful protest from the 1970s.

Roman politician Herodes Atticus built this nymphaeum to honor his wife, whom he may have murdered.

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

This ancient trail climbs the mountain where a Latin League cult worshipped Jupiter, its main deity.

A magnificent waterfall is also home to the remains of a Roman hydraulic engineering system.

In Rome’s Jewish ghetto, a 200-year-old bakery still makes the neighborhood’s historic sweets.

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

This former Roman Catholic Church still contains the embalmed hearts and organs of 22 popes.

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

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

Hundreds of lucky felines haunt the ruins where Caesar was murdered.