An "inside out" building in the historical center of Paris, featuring Europe’s largest modern art museum.

The oldest stone house in Paris was built by its most famous alchemist.

This medieval castle was home to a known tyrant and features several hidden passages.

A monument to the migrants who cross the dangerous waters between North Africa and a tiny Italian island.

In Florence's great Duomo, a 26 foot fresco honors a mercenary famous for attacking Florence.

This one-of-a-kind archeological site is home to strange prehistoric ruins, the original use of which is still a mystery.

An unusual "skull with ears" sits in the crypt of this small church tucked away at the end of a narrow alley.

Sleep amongst an abundance of art from the modern era.

The bones of some 7,000 soldiers killed in the historic Battle of Solferino are stored here.

Hanging within this medieval church are the bones of a beast allegedly slain by a fourth-century saint.

Gods clash with machines in a power plant regenerated as a museum.

A stunning cemetery famous for its extraordinarily delicate & lifelike mourning sculptures.

A star-shaped fortress town fort built in the geometric model of the Renaissance utopian city.

Italian cave with exceptional acoustics and an unsavory history.

A Nesting Doll of Churches.

Natural cathedral designed by Italian artist Giuliano Mauri.

Thousands of well-dressed mummies below a monastery.

According to the local folklore, the myriad colors of this lake are the result of a lovelorn wizard's blunder.

Brass cobblestones mark the places where individual Holocaust victims were taken from their homes.

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

Dramatic sea stacks adorn the coast of this small village on the Adriatic coast.

Dug as a secret royal escape route, the tunnel became a wartime bomb shelter and dumping ground for vintage cars.

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

David Sedaris called it "The greatest shop in the world."