A subterranean relic of the Spanish Civil War hides below this picturesque park.

This embalmed man is one of the best preserved mummies from the Canary Islands.

Earth's rocky history has rarely glittered so brightly as it does in this Spanish museum.

One of the world's oldest universities houses an incredible collection of anatomical models, mummified body parts, and human bones.

The oldest restaurant in the world is this old-world Spanish eatery, still known for its suckling pig.

Madrid's romantically ornate crystal palace has been offering shelter to plants and art for over a century.

The morbid items in this small and hidden museum are not for the weak stomached.

The world's smallest movie theater runs on solar power—an attraction in itself.

This shell of a historic manor house on the Isle of Wight is said to be the most haunted site on the island.

"Purveyors of traditional sweets and vintage treats."

Created hundreds of years ago, the magical follies and landscapes at this park were almost lost to time before being restored.

The biggest and deepest Cold War bunker open to the public can be found in southeast England.

This tangled English forest looks like something right out of a fairytale.

The elaborate clockwork contraptions in this Scottish gallery create small worlds of whimsy and horror.

This beautiful "lagoon" is actually a toxic soup filled with cars, carcasses, and trash. When warnings couldn't stop people from going for a dip, the town dyed it black.

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

The perfectly preserved underground rooms where Churchill plotted the war against Germany.

The largest greenhouse in the world is home to over one million types of plants.

The most iconic structure in Scotland has been home to bishops, colonels, and Sean Connery characters.

A modern English garden of eccentric beasts, follies, and oddities.

The curios of pharmacist and collector Henry Wellcome.

The sign at the garden gate reads: "These Plants Can Kill."

Amazing and mysterious Neolithic settlement on Scotland's Orkney Islands.

The hidden "ballroom" under a mansion lake was built by a criminal who ate a cyanide pill during his trial.