It's not hard to see why the historic Peabody Conservatory of Music's library has been described as a "cathedral of books."

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

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.

This Budapest bar allows drinkers to leave their mark on the walls, floor, and even ceiling.

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

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

A saintly relic hidden in a Prague church basement.

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

Despite attempts by local police to discourage it, Beatles-inspired graffiti has been a means for artists to air grievances for decades.

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

The first museum in the world devoted to sexual gadgetry.

This little museum is making sure that the art and history of the graffiti sticker is not scraped from history.

Home to 10,000 medical specimens including the remains of Rudolf Virchow's extensive collection of pathological specimens.

This classic restaurant features a gorgeous mirror-clad room.

An old department store turned Nazi prison turned artist commune.

A slice of central Asia in the middle of Berlin.

A whimsical and twisted animatronic monster tour beneath the streets of Berlin.

A fascinating insight into daily life in the Eastern Bloc.

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