A narrow passage next to a cafe leads to a courtyard exploding with murals, tags, and paste-ups.

A state-of-the-art medical facility from the Imperial era is now a derelict ruin.

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

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

A surreal museum of extraordinary industrial objects.

Started as a kitchen garden, now the second largest botanical garden in the world.

This futuristic German spa allows visitors to float in a pool of salt water while zoning out to underwater techno.

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

This charming fountain honors Felix Salten, the creator of the iconic storybook deer.

One of a series of no-purpose kinetic artworks by Swiss sculptor Jean Tinguely.

Vines grow up the metal bars in this public park created from an old machine factory.

Sealing couples' love since just after World War I.

This spaceship-like Serbian monument reaches for the stars in celebration of the fallen fighters of fascism.

Nikola Tesla's ashes are held in a golden sphere, surrounded by his works.

A towering spire in the fortress of Kalemegdan honors the victorious armies of Serbia during their struggles against the Ottoman Empire.

The place where World War I began.

A number of craters left by fatal mortar strikes have been filled with red resin to remember those lost during the Siege of Sarajevo.

A pair of connected skyscrapers form this symbolic gateway.

Destroyed Serbian army headquarters sits half crumbled in a largely revitalized Belgrade.

A small memorial to a deadly night in Serbia that shook the world before it was swept under the rug.

A misnamed well, with a deep dark past.

Oriental bazaar in the heart of Sarajevo.

This historic timepiece is thought to be the only public clock in the world that keeps lunar time.

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