A historic house left in "dramatic still life."

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

Hidden in a grotto 26 feet below Nottingham's oldest hotel, this stylish subterranean drinking den is notoriously hard to find.

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

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

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

The longest hedge maze in the world.

This wildly-tiled artist's palace is a living and growing account of the creator's life, loves, and labors.

In this cobwebbed old operating theater, you can practically hear the screams of the unanesthetized patients.

Remnants of a Victorian garden feature sitting in public woodland.

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

A hands-off space for graffiti artists to hone and display their skills.

The world's largest collection of witchcraft regalia.

A vast overgrown cemetery, once known as one of London's "Magnificent Seven."

A student driver's nightmare.

One part local history, 99 parts gruesome haunted house.

This South London cemetery holds the remains of more than 15,000 people.

Hidden beneath the streets of London is a secret subway that only carried mail.

Banksy gives themself artistic license with this piece of London street art.

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

This collection of illusory paraphernalia has been culled from the history of London's premier magician's club.

A kaleidoscopic warehouse-maze of handmade neon signs.

The mysterious, fantastical woodland inspiration for "The Lord of the Rings."

Every Easter, a small Sicilian town builds a stunning cathedral out of bread.