One of Scotland's most important modern structures, it just made the '100 Most Endangered Sites' list.

This abandoned mausoleum from 1815 sits deep within the forest surrounding Callendar House.

A strange rock with a sinister reputation lurks within the crimson waters of this Scottish glen.

A once extravagant mansion, now reduced to ruin.

A long-abandoned relic of World War II.

A mysterious monument where a woman who records say never existed was burnt alive for being a witch.

Harry Potter once visited this massive limestone cliff, which was carved by an ancient glacial river.

This iconic 1,000-year-old medieval castle is a favorite of the film industry, most notably as the location for Hogwarts in Harry Potter.

Now famous as the "Harry Potter bridge," this impressive concrete viaduct has long been an icon in its own right.

A reportedly haunted 14th century church is curiously facing the “wrong direction.”

A large piece of modern art makes this roundabout the only one in the world with its own laser.

Climb to the top of this windmill for a scenic panorama and up-close look at wind energy production.

This crumbling coast and its teetering tower are literally filled with history, but they are also at great risk of becoming history themselves.

The scene of the United Kingdom's most famous UFO incident, dubbed the "British Roswell."

A 17th-century church is nestled within the walls of a 15th-century ruin.

A mysterious crater-like pond has a spooky tendency to empty and fill with complete disregard to rainfall patterns.

The intended purpose of this unfinished Elizabethan building remains a mystery.

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

An abandoned 18th century manse looks like something out of an Indiana Jones movie.

A quartet of rusting satellite goliaths are all that remain of a communication network that protected Britain from German and Russian air strikes.

The gloomy ruins that inspired Bram Stoker to bring Dracula to life.

Built in 1911, the Tees Transporter Bridge is one of only six transporter bridges still in operation.

Derelict chemical plant on the North Sea is a beautiful industrial ruin.

This abandoned asylum was once a state of the art facility before devolving into one of the most deadly mental institutions in American history.