The martyr's wax-enhanced skeletal remains lie preserved in a glass case in the Santa Maria della Vittoria in Rome.

A collection of objects supposedly singed by the hands of souls in purgatory.

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

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

Architectural monsters are devouring this palace's every door and window.

This hill made entirely of ancient Roman jars was simply a garbage dump to the people of the time.

The only "Egyptian" pyramid in Europe and the legendary tomb of Remus.

The "Great Sewer" of ancient Rome is one of the oldest sewer systems in the world, and is still in use.

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

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

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.

An interactive exhibition space dedicated to the kinetic sculptures of Swiss artist Jean Tinguely.

This tribute to the 16th-century composer is now an unusual shrine to Michael Jackson.

The final resting place of more than 200,000 people, this is one of the largest cemeteries in Europe.

A hidden art gallery in an abandoned Warsaw fort.

A national collection of Communist-era musical posters.

A tribute to the Polish insurgents who fought in the failed attempt to end their city's Nazi occupation.

This hidden collection of everyday objects illustrates life within communist Poland.

The world’s narrowest house makes for an awkward, four-foot-wide living space.

A 20th-century picture show in 3-D.

In the summer, the area around this sculpture transforms into a vibrant concert venue.

This bell stars in a tragic love tale and is said to make wishes come true.

These 18th-century paintings of Warsaw were used to reconstruct the city after World War II.