Be(w)ar(e) the moat around this historic Czech castle.

A clerical error gave rise to this imaginary micronation in the southwestern corner of Estonia.

A hidden tunnel leads to a medieval queen's shrine buried beneath a parking lot.

A medieval bridge stretches over a sulfur-rich river that leads to year-round natural hot springs.

London's creepiest cemetery was once the site of dueling magicians and mobs of stake-carrying vampire hunters.

Remnants of a Victorian garden feature sitting in public woodland.

Wedged between two buildings at the Great Ormond Street Hospital is this secret music installation.

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

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

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

Several plaster noses are hidden in plain sight around London's Soho neighborhood.

The world's first underground farm is in a World War II bomb shelter beneath the streets of London.

Shakespeare, David Bowie, Dr. Who, the Saxons, Druids and Romans are all claimed to have all made their mark on these massive man made tunnels.

This series of Scottish caves has no clear purpose other than baffling historians.

The highest peak in Northern Ireland is topped with a stone tower and haunting burial mounds.

The atmospheric road was never meant to be so creepy.

A stairway to heaven, or to nowhere at all.

A house of bones — but nobody is quite sure to whom they belong.

The longest hedge maze in the world.

This Russian diner is staffed entirely by twins.

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

Thrilling and delicious complement to any dining experience.

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

England's oldest surviving hedge maze has been confusing visitors for over 300 years.