Thousands of coffin-like pillars make up this controversial Holocaust memorial.

A museum dedicated to the history of a terrifying secret police is now held in their former headquarters.

A tour of underground Berlin takes you through WWII air raid shelters and tunnels used to smuggle people out of East Germany.

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

A surreal museum of extraordinary industrial objects.

The most visited, and possibly most controversial, museum in Germany.

For one day every month Barcelona's Estació de França transforms into a market for model trains.

An eclectic collection of thousands of items owned by the sculptor Frederic Marès.

A once grand hotel now sits eerily abandoned in the Catalan countryside outside Barcelona.

One of Europe's largest supercomputers is housed inside of a disused chapel.

The 2,000-year-old Roman columns are hidden within Barcelona's Gothic Quarter.

Bask in the 19th century grandeur of an eccentric Freemason millionaire's private gardens.

Leave the wardrobes and sweets to British schoolchildren, Shanghai's got a Coke machine that leads to booze.

Hidden in plain sight on a pair of Manhattan subway tunnels are a pair of public instruments that sing to each other.

One of New York's best collections of pinball is hidden in a secret bar in the back of this laundromat.

The only parking meter in the entire town, it is surrounded by 100 free spaces.

An old vending machine serves up unpredictable beverages from its seemingly magical insides.

This upscale streetwear store is hidden behind a fake Snapple machine in the back of a deli.

The signs of a long buried road can still be found hidden beneath a London sewer grate.

Great Britain's only hat-making museum.

Medical and zoological curiosities for sale.

This museum houses an imposing skeleton army comprised of creatures great and small.

Theme park featuring miniature replicas of European monuments.

Three floors of musical instruments coming from all corners of the world and hundreds of years of musical history.