The Pope’s secret escape route.

This hydrochronometer was invented by a Dominican monk and is a prime feature in this garden.

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.

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

The underground sanctuary of a mysterious ancient cult.

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

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

This strange bovine gargoyle is said to have been put in as a passive aggressive form of revenge.

A 14th-century abbey founded by a forest-loving order of monks now sits in the center of a pristine nature preserve.

A whale rib was used to advertise the store by the arch that offered exotic goods from far away.

These elaborate gothic monuments honor Verona's medieval lords.

Not far from the more famous House of Juliet, visitors will find the supposed residence of her lover.

It’s said this crypt was the setting for the tragic finale of the Shakespeare play.

This medieval castle was reconstructed by Carlo Scarpa.

A secret hatch containing two parchments was discovered in this statue over 40 years after its installation.

This network of roads is one of the most unique Etruscan creations ever discovered.

Charles Dickens was not a fan of the ghastly wall dressings in this 6th century church.

More sculpture than building, this architecturally significant temple was built on the spot of Saint Peter's crucifixion.

Rome's semi-secret peephole vista is also a former Crusader stronghold.

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

Behind medieval walls in a corner of bustling Palermo is a breathtaking former mosque once inhabited by a wolf-taming hermit.

Naturally preserved bodies are eerily staged throughout the crypt in varying poses.

A spiritual sanctuary in a natural cave.