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

The painter of "The Scream" is laid to rest under a stoic bust of himself in the humble corner of an Oslo cemetery.

A wonderfully strange collection of 500+ stuffed frogs doing people things.

One of the oldest used bookstores in the U.S. has been selling antiquarian treasures since 1825.

One of the dwarven trees dates back to 1625 and survived the Hiroshima bombing.

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

A wunderkammer of gold and silver reliquaries and ancient saintly bones.

An eclectic art form practiced by untrained masters is celebrated at this museum in the heart of Zagreb's old Upper Town.

This Hungarian castle was built out of cardboard and wood until it proved so popular that it got upgraded to stone.

The romantic garden was the epicenter of the Hungarian art scene in the 1880s.

A 19th century artistocrat's mansion, turned into a library, hidden in a modern library.

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

A Hungarian pharmacy museum with a box full of mummy powder.

A series of caves under Castle Hill that once held the prisoner Vlad Tepes, better known as Count Dracula.

The Habsburgs' royal collections of art and wonders.

Located right outside of Vienna, visitors can take in expansive views of an ethereal forest.

The former private quarters and office of Dr. Sigmund Freud now hosts a museum housing the works of the founding father of psychoanalysis.

The resting place for anonymous victims of the Danube's dark waters.

The topiary maze at the Habsburg hunting lodge.

The crypt of the imposing Stephensdom holds royal intestines and thousands of skeletons.

The beautiful baroque library of the Hapsburg empire.

A bust of Franz Kafka spins in pieces, reflecting the writer's inner torment.

Countless grotesque faces stare out from this eerie Prague art wall.

Two stunning 17th-century libraries and a cabinet of curiosities.