St. Mary's Asylum was isolated and abandoned before being converted into a Bed and Breakfast.

The ruins of an abandoned crematorium haunt an eerie deserted German cemetery.

This real life asylum of horrors is now an abandoned ruin that hides the unbreakable code to one patient's insanity.

One of the most easily accessible examples of the rare 1960s UFO houses.

These bronze pamphlets remember a remarkable group of Germans who fearlessly opposed the Nazis in the very center of their power.

Macabre astrological automaton clock dating to the late 1400s.

The vast chamber inside this abandoned cooling tower looks like something out of a sci-fi dystopia.

The abandoned "Ghost Mansion" was left to decay in the mountains of Northern Italy.

Unfinished monument to peace between Turkey and Armenia, long divided by a dispute over genocide.

This beautiful train graveyard is one of the largest collections of steam locomotives in the Mediterranean and Europe.

Mediterranean castle on a tiny Turkish island.

The only university zoological museum in London houses extinct animals, bizarre natural history specimens, and a Micrarium of microscopic creatures.

This English medieval castle is where King John died of dysentery.

This abandoned coliseum was intended to be a grand Nazi rallying ground before it was halted at the end of the war.

The world's first jet-powered aircraft were assembled by the Germans in this secret factory in the forest during WWII.

This shuttered power plant is now Turkey's first industrial archaeology museum.

This former Imperial summer home was the venue for a royal slap that once echoed 'round the world.

This hidden gem is bathed in beautiful natural light.

One of the largest wooden constructions in Europe was meant to be a casino, but soon became an orphanage.

The ancient abodes are a testament to human ingenuity amid harsh climates.

A Turkish monastery tucked into a cliff wall.

A Turkish ghost town abandoned in a population exchange with Greece.

Once described as the "Eagle's Nest," this ruined ancient city rests on a remote mountaintop.

A small etching on the white marble parapet was written in runic script by a Viking mercenary.