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

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

The smaller of the three towers of San Marino is a former prison inaccessible from the ground level.

Model Trains and Much More in Hamburg.

What looks like a normal building is really a hollow facade hiding a subway vent.

This bridge was constructed from the rubble of the infamous Bastille.

France's national museum of scientific and industrial instruments.

The vast, legendary catacombs hold secrets much stranger than stacked bones.

The biggest and deepest Cold War bunker open to the public can be found in southeast England.

The National Railway Museum in York is the largest railway museum in the world, attracting almost 1 million visitors per year.

The little-known second castle that William the Conqueror built in York.

Semaphore saints, a golden dragon's head, and a stone carved with religious warnings all call this cathedral home.

This memorial to World War II's fallen airmen shows us the movements of the stars that once guided them.

This sculpture marks the spot where one of the greatest Roman rulers was proclaimed emperor.

The remains of an ancient bathhouse sit inside this aptly-named pub.

This network of narrow, medieval passages has the most delightful name.

Makers and sellers of the original and finest York Ghosts.

The final resting place of England's most notorious bandit.

Follow the original medieval paths that wind through this intriguing section of the city.

One of the shortest streets in York has an especially odd name.