Once the grandest synagogue in medieval Spain, it now stands as a memorial of the 15th-century Jewish exile.

A display of torture devices used in the Spanish Inquisition and other scourges of medieval Europe.

A monumental fountain in Rome features a large statue of Moses that has been criticized for centuries.

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

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

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

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

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

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

The secret medieval communication system will whisk your words above the noise of the crowd.

An ossuary built in 1210 to collect bones from the Ospedale Maggiore of Milan.

Erotic art covers the walls of the largest ancient pleasure palace.

The walls and streets of the ancient city are peppered with penises.

This amazingly well-preserved villa just outside Pompeii boasts rare examples of ancient Roman paintings.

Before it was buried by volcanic ash, this fast-food restaurant fed the hungry hordes of ancient Rome.

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

The once forbidden "secret cabinet" of erotic art from excavations of Pompeii and Herculaneum.

This small Estonian hill is covered in hand-made twig crosses that are said to bring good luck.

How did a French journalist’s grave become the sexiest statue in the cemetery?

A museum of carnival attractions where you are invited to ride the rides.

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

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

This Roman statue is missing a limb from when the Venetians stole it from Constantinople during the Crusades.

View the ancient remains of buildings and the ancient "River of Hades" before hopping on a train.