At high tide this strange footbridge appears to have no purpose whatsoever.

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

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

Giant, friendly pelicans in Central London, the most unlikely of places.

This hidden green space is the city's second largest conservatory.

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

A subterranean playground in an abandoned slate mine.

The highest peak in the United Kingdom has a history of physics, specters, and a pilgrimage of strange objects.

The Metropolitan Police refurbished the blue box (perhaps not coincidentally) the same year "Doctor Who" returned to TV screens.

Mysteriously stacked storefront paths give this medieval British town an iconic style like none other.

Accessible only at low tide, the deserted island is dotted with World War II ruins.

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

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

The remains of Crystal Palace Great Exhibition of 1851.

Surreal riveted sea forts once protected the Kent shores from German attack.

The largest of London's subterranean rivers and once a mad, bad center of London life.

The signs of a long buried road can still be found hidden beneath a London sewer grate.

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

Northern Ireland's Brobdingnagian stepping stones.

A charming 17th-century alley is lined with secondhand bookstores and antiquarian shops.

A tongue-in-cheek arcade where the games are based on everyday life.

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

A 30-acre garden inspired by the principles of modern physics.

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