The world's oldest bookshop still in operation.

Ring the bell to enter a bar that looks equal parts museum and old curiosity shop.

This unreal Portuguese palace looks as though it's made from a pile of different castles.

A 16th century chapel decorated with bones, skulls, and entire bodies hanging from the wall.

Houses are tucked between, on, and underneath giant boulders.

This eccentrically decorated palace is replete with grottoes, fountains, tunnels, and caves.

An old slaughterhouse now holds the largest collection of pig artifacts.

The first museum in the world devoted to sexual gadgetry.

Disused seaplane hangar gets a second life as the jaw-dropping home of Estonia's museum of maritime history.

This restored house is like a time capsule of the president's unconventional inauguration.

This edgy museum will whet your appetite for the industrial history of Western New York.

The old castle kitchen where nucleic acid was first isolated is considered the "cradle of biochemistry."

This bar and museum are devoted to the controversial comic book work of Kája Saudek.

This doorless 20th-century elevator doesn't stop or slow down.

Around 100,000 bodies are buried below the medieval headstones, many of which mark graves with multiple bodies stacked up to 12 deep.

Walk through Czech history in Prague's largest graveyard.

The hidden lair of an alchemist rediscovered in a 2002 flood.

A Jenga-style cylindrical tower of books that appears to go on forever.

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

Macabre astrological automaton clock dating to the late 1400s.

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

The history of occult science is turned into a creepshow at this lurid Prague tourist attraction.

Where once there was a train station bathroom, there is now this German burger joint.

The largest free-standing aquarium in the world resides in a hotel lobby in Berlin.