Martin Bricelj Baraga's monolithic sculpture measures the blueness of the sky, and changes color to match it.

This abandoned Slovenian military barracks has become a punky-political art squat.

This former estate of a fascist leader is now a burnt out ruin leading to a system of secret tunnels.

Where the lovelorn find a home for their sentimental keepsakes.

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

This only museum in the world dedicated solely to mushrooms.

A peculiar museum that includes many drunken tales, a drunk driving simulator, and much more.

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

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

The true meaning behind this sculpture remains unknown.

This quaint Hungarian railway system is operated exclusively by children between the ages of 10 and 14.

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

Floating swimming pool within a moored vessel.

The abandoned remains of this Victorian brewery hide crumbling bowling alleys and rusting industrial gear.

The best bagels in Berlin are tucked away in an independent bookstore.

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

A floating cat sanctuary on an Amsterdam canal.

Where royalty waits in the height of luxury.

One of Amsterdam's narrowest houses is located right across the canal from its widest.

A Dutch passageway's artistic, aquatic-themed makeover pays tribute to the capital city's famed waterways.

The world's first zoo for microbes collecting the horrible and wonderful things living on and around us.

This subterranean studio is filled with fascinating kinetic art.

This museum inside Amsterdam's largest cemetery explores how people deal with death.

Cat art as far as the eye can see.