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

A pagan tradition of draping trees with rags eerily lives on.

The heads of two giant mythological water horses honor Scotland's horselord past.

A rocky sea serpent hides caves, blowholes, and a spectacular natural bridge.

A book bound in the skin of an infamous criminal, along with countless other specimens.

Mary Kelly was last seen here before she was murdered by Jack the Ripper.

The one-time stronghold of the noble Douglas family, now home to ghost sightings and nesting birds.

Islanders once used this dramatic, otherworldly landscape to hide their cattle from Viking raiders.

Once thought to be the mysterious work of a witchy prophetess, a well with unusual properties turns objects into "stone".

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

The television series' iconic giant foot was borrowed from this classical painting.

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

One of the world's largest collections of pathological specimens.

A collection dedicated to the treatment of disease, held in London's oldest hospital.

The ruins of this gorgeous clifftop castle look like something from a fantasy novel.

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

An Oxford museum where visitors can have tea with the Mad Hatter and climb through the wardrobe to a fantasy land.

A mysterious artist-run cabinet of curiosities and library.

The final resting place to 300 Victorian-era pets hides inside the city park.

A historic London pub with prison cells in the cellar and a "spy room" on the second floor.

The anatomical-pathological collection of a man who changed surgery.

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

A island reachable by a causeway at low tide is possibly one of the earliest Western European locations to be identified in text.

Catacombs turned marketplace.