An 18th-century post box used to alert the church of sick and ailing foreign pilgrims.

A massive marble foot is tucked away in a small alley near the Pantheon.

Plaques on its facade commemorate the Tiber's most destructive deluges.

A detailed pachyderm supports Rome's smallest Egyptian obelisk.

This hidden alley near the location of Rome's first theater was the site of a curious miracle.

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

An unremarkable wooden wheel built into the side of one of Rome's oldest hospitals was part of a policy to reduce infant exposure.

This small, ancient Roman temple was once a church dedicated to the patron saint of penitents.

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

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

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

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

Its interior is adorned with some of the best examples of early Christian mosaics.

The crypts of Capuchin friars decorated with the bones of over 4,000 friars, including an entire "crypt of pelvises."

An ancient Egyptian obelisk is now used to commemorate fallen Italian soldiers.

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

A monumental fountain in Rome features a large statue of Moses that has been criticized for centuries.

A sculpture serving as an homage to Pope John Paul II.

Inside this McDonald's you can dine on your Big Mac and fries next to a 2,500-year-old Roman wall.

This amazingly well-preserved villa just outside Pompeii boasts rare examples of ancient Roman paintings.

The last moments of the ill-fated Pompeiians, frozen forever in plaster.

Erotic art covers the walls of the largest ancient pleasure palace.