Despite being pillaged and destroyed a number over times down the centuries, this historic church still sort of stands.

A Red Cross memorial museum at the site of the Niš concentration camp that operated for four eventful years during World War II.

The bizarre rocks of Đavolja Varoš are the result of natural erosion.

A Serbian church lit by chandeliers made of weapons.

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

Structure built from the skulls of vanquished foes.

This 14th century castle withstood years of battle but is now sliding off the hills into the Danube.

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.

The music is over at the Ballhaus Riviera Ballroom, but the ballroom remains in haunting disrepair.

Art and a pun, all in one.

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

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

A surreal museum of extraordinary industrial objects.

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

An eerie, derelict amusement park in Berlin.

The only museum with its curator—and her pets—buried inside.

This palatial spiral staircase was so unusual the name "snail" was given to the noble family who built it.

This abandoned island off the Venetian coast has been a radical monastery, a political prison, and a secret Nazi base.

Venice's "Island of the Mad."

This community on a small Venetian island has taken to painting their houses in bright neon hues.

A small island less than half a mile from Venice is a forbidden island with a dark and twisted past.

A new sculpture calls attention to climate change in the centuries-old city it threatens.