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

A small cell adjacent to this church was once the bedroom for a renowned saint.

An ancient Roman temple first dedicated to an emperor's wife is now a church.

A town saturated in Italian rationalist architecture was once marshland drained by Mussolini.

This one-of-a-kind Roman arch is not actually dedicated to the god Janus.

One of ancient Etruria's most spectacular archaeological sites with impressive necropolises and rugged landscape.

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

The pile of books behind the dignified writer gave the statue a most undignified nickname.

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

Was this cave created by Hercules's wrath, the devil, or volcanic activity?

Next to the Leaning Tower of Pisa is a cemetery home to ancient sarcophagi and disturbing murals.

This gallery commissioned by Cardinal Spada is known for its magnificent optical illusion.

The ruins of the largest gladiatorial school in Rome are largely hidden under modern streets.

A medieval, mosaic-lined baptistry built by a heretical Christian sect.

Psychoanalyst Carl Jung reported a paranormal experience after visiting this mosaic-lined Roman baptistry.

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

In the early Roman Empire, people deemed traitors and criminals were tossed to their deaths from this rock.

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

Italy's third-largest Roman arena gives a peek into the underground operations beneath the ancient spectacles.

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

An incredible mosaic-lined monument said to have held the remains of an ancient Roman empress.

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

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

Romans decided this 16th-century "talking statue" was so ugly, they named it after a primate.