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

An ancient necropolis of magnificent tombs.

An abandoned 1920s school with a mysterious history.

Sacked by Vikings, blessed by William the Conqueror, dealt a fatal blow during the French Revolution—these ruins have seen it all.

One of the cave cities of Crimea, built by the Goths in the sixth century.

A quaint Russian village in the middle of a German metropolis.

This German bone house contains the remains of some 20,000 souls.

A German apartment building hosting as many trees as human occupants.

This Nazi-built amphitheater was constructed on a sacred mountain site used by various German cults.

What was once thought to be a wellspring of unicorn bones is actually just a prehistoric burial site.

No need to strap in for a "ride" on this walkable roller coaster.

This historic stone bridge has an entire neighborhood clinging to its sides.

Terrifying derelict military hospital once housed a recuperating Hitler.

A church filled with the bones of hundreds of virgins martyrs—or so they say.

Soaring over 6,000 feet in the Bavarian Alps, this beer garden was once Hitler's 50th birthday present.

An intricate and amazing house built by architect Karl Junker.

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

This medieval castle overlooking the Elzbach river looks just like it did hundreds of years ago.

Ruins of a German Castle on top of a towering stone pillar.

The birthplace of an eccentric alchemist and possible inspiration for the fictional reanimator of monsters.

This Georgian Gothic building was created to shelter and feed deer.

A mysterious architectural gem in one of the most elegant areas of Buenos Aires.

The Roman Emperor's lost summer home and grotto full of enormous sculptures sit along the Italian seashore.

This underwater graveyard commemorates a group of murdered 16th-century missionaries.