One of Antoni Gaudí's most classic buildings is well-known for its "dragon-back" design.

This home designed for chocolate magnate Antoni Amatller is an exquisite treasure-box of Catalan Modernism.

The iconic boulevard is the perfect place to catch sight of a bicycling skeleton, a levitating Satan, or a chef with his head stuck in a pizza.

On the wall of this medieval walkway, a symbol of the Spanish Inquisition.

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

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

Protecting the dead from opportunistic body snatchers.

Eyam took steps to quarantine themselves and keep the plague from spreading.

These "anatomical machines" are only one of the many strange items in this Italian crypt.

The Neapolitan Cult of the Dead still cares for the skulls at this mini-Fontanelle.

A Trabant car, a kangaroo statue, and a plethora of plants take over this abandoned-factory-turned-bar.

Once the home of a hermetic monk, this cave now houses a small church.

From Austrians to Nazis to Soviets, this historic Budapest fortress has a history as complex as the city itself.

A statue in Budapest's Liberty Square honors the former U.S. president's efforts to end the Cold War.

The mummified right fist of a 1,000-year-old saint-king sits inside an ornate golden reliquary.

Tucked away near more famous landmarks lies a statue meant to symbolize the confluence and continuing development of human culture.

A trail of iron footwear stands as a monument to the thousands executed along this riverbank during WWII.

A museum dedicated to a secret military hospital hidden beneath a castle in Budapest.

Built in 1870 at the bridge that connected Buda and Pest, this spectacular incline railway was almost lost forever during World War II.

Blitzkrieg bop your way through Berlin's Ramones Museum.

Copenhagen's celebrated theme park and gardens.

The final resting place of the author who gave us the Little Mermaid, the Ugly Duckling, and many more beloved fairy tales.

Danish tourist destination well known for open stalls where vendors sell marijuana on the street.

A stretch of land where the sour-sweet vegetable is cloaked in darkness and grows so fast you can hear it crack, squeak, and pop.