A 16th-century horror show built in a lovely Italian garden.

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.

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

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

This Italian stadium makes liberal use of fascist statuary to evoke classical sporting arenas.

A treasure trove of Renaissance-era funerary art in a Roman church built on top of Nero's grave.

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.

This medieval church in Rome was almost destroyed following a terrorist attack in 1993.

This ancient Roman arch misled treasure hunters for centuries.

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

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.

An alchemist's "magic door" stands in the middle of a Roman park.

Ancient paintings known as the "Sistine Chapel of Cave Art."

A 14th century bridge built as a fortress, where the devil lurks on one of its towers.

Historic medieval fortified city in southwest France.

This Parisian gem is one of the most incredible ethnographic museums in the world.

France's most famous cemetery, with some of its most curious tombs.

The ruins of a Duke's bucolic dream, where camels once roamed alongside "Dutch" windmills and faux-Italian vineyards.

A Parisian cemetery where the elite and artistic are interred beneath an eccentric collection of tombs.

Medieval museum built over Roman baths that features famous tapestries of a lady and a unicorn.