This remote castle was built to be a wealthy businessman's palace of vice but is now simply a historic vacation cottage.

An abandoned quarrying village turned commune is now a hub for learning the Welsh language.

In an arboretum with hundreds of memorials to the fallen, this one might be the most poignant.

This tiny 1930s Art Deco airport is a beautiful remnant of a bygone era.

A brisk climb up this solitary peak leads to the origin story of a towering figure in Irish history.

The UK's oldest theme park slowly slips away.

A remote island holds what claims to be Scotland's smallest cinema.

A baffling beast so absurd a town councilman called it "intellectual vomit in technicolor."

This centuries-old hotel hides a network of secret cellars and passages once used by smugglers.

Displaced highlanders would take shelter from the wet Scottish climate under the large walled bridge at Glasgow Central Station.

The site of a mysterious pony massacre is rich with extraterrestrial conspiracy theories.

A boutique perfumery fashioned to look like a Victorian-era shop.

This strategically placed hill fort has served defensive forces from the Iron Age up until the 20th century.

An 18th-century lighthouse built on a 16th-century castle is now a monument to the maritime beacons of Scotland.

This picturesque horseshoe weir was first built in the 1600s to prevent flooding in the town of Bath.

The lake that fills and empties itself at random.

This stretch of the River Severn where large waves flow against the current is the birthplace of river surfing.

This Scottish castle has witnessed clan rivalries, Jacobite uprisings, whisky smuggling, and more.

The commemorative stone column conceals a secret laboratory.

This ruined folly was originally built to honor a failed American state that would have become "Westsylvania."

The colorful stairs are made with marble from the world's major quarries.

This volcanic plug boasts the longest recorded history of any Scottish stronghold.

The abandoned transportation hub hides within the Glasgow attraction it once served.

There are hundreds of secret WWII bases hidden in British forests. Built to fight a Nazi invasion, they remained unknown for decades.