A subterranean playground in an abandoned slate mine.

The highest peak in Wales is said to be the final resting place of a giant killed by King Arthur.

This abandoned asylum in Wales might look haunted, but it's still beautiful.

Abandoned ship reimagined as a street art canvas.

The decaying ruins of Wales' first asylum for the mentally ill.

Hidden on the urban banks of a Manchester river are a series of abandoned waterside industrial sites.

This derelict superstructure was a very important warning system for the Soviet military.

The ghost town left by the worst nuclear disaster of all time is being taken over by nature and urban explorers.

This attraction was abandoned after the Chornobyl disaster.

One of the most poignant ruins of the Chornobyl nuclear disaster, the local football team's stadium has been quickly reclaimed by nature.

Manchester's abandoned train depot lingers in a post-industrial purgatory.

This aging storage facility is the world's largest brick warehouse.

A metal tree emits eerie, melodic notes on top of Lancashire's Crown Point.

The last of the 19th-century booze-free bars has been slinging teetotal tonics for over a century.

One of the oldest amusement rides in existence was a huge disappointment to its creator.

The second-longest pier in the U.K. stretches a whole kilometer into the Irish Sea.

This hospital once pioneered the use of electroencephalograms, but fell into maltreatment, abuse, and eventual abandonment.