A open air theatre built on a cliff by an eccentric British woman.

A remarkably well preserved tower dating all the way back to the Iron Age.

An abandoned tank sits in an empty London lot as a symbolic middle finger to local city planners.

A scattered trail of street art adds a pop of color to the city's stark structures.

Old-fashioned knowledge and modern engineering create the world's only rotating boatlift.

Three bridges straddle a stream, one stacked upon the other.

This home on a quiet suburban street is completely covered with vibrant mosaics.

A hermit's tiny cell built into the cliffside that saved him in South Pembrokeshire.

Pop culture has helped to keep this iconic British building from being destroyed.

Below a historic English market town lies a secret underground city complete with kitchens, laundries, storerooms, and an underground lake.

The John Snow Memorial marks the epicenter of London's 1854 cholera epidemic.

A network of concealed passageways lies within a busy London Underground station.

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

This small museum in a former church crypt contains artifacts of the Elephant Man, Jack the Ripper and Florence Nightingale.

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.

A unique waterfall that some believe attracts the fairfolk.

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

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

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

The remains of Crystal Palace Great Exhibition of 1851.

Ancient cliffs resembling a kilt on Scotland's second largest island emit an entrancing sound.

Spend the night in this formerly abandoned traditional Scottish village.

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