Deep in the countryside lie the remains of one of the grandest Roman dwellings in Britain.

Now nearly dry, this lake is said to be the ancient home of the Lady of the Lake, and was once thought to be bottomless.

The smallest pub in Britain was once a cabinet of curiosities and it still has the dead cat to prove it.

Grotto replete with mystical designs laid out in glued shell mosaics.

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

This Scottish burial tomb once held hundreds of ancient eagle bones.

Europe's largest prehistoric mound – burial site of a legendary king?

19th-century scientists would make the pilgrimage here to verify the precision of their measuring sticks.

This tiny island featuring 9th-century Viking ruins is only accessible at low tide.

Near Birmingham, England three and a half miles of top-secret tunnels housed a World War II “shadow factory” and a Cold War nuclear bunker.

Numberless clock creates a meal of time for the dreaded, insectile Chronophage.

This silent sentry in the crypt below a large Gothic cathedral is often knee-deep in water.

This tiny little pool is said to be home to a malicious mermaid named Jenny Greenteeth.

This logic-defying 16th-century Tudor manor still stands to the delight and astonishment of onlookers.

The largest known medieval map of the world.

Macbeth's infamous "Great Birnam Wood."

This antique prison is a tourist attraction with a sordid past.

The ruins of this medieval castle in Northern Ireland have inspired artists from C.S. Lewis to Led Zeppelin.

This one has sailed five times as far as Sir Francis Drake's famous ship.

A red sandstone freestanding monolith rises out of the sea in northern Scotland.

Sometimes an island, sometimes a rocky outcropping connected to the world by a tiny suspension bridge.

A hidden tunnel leads to an abandoned slate quarry that's now a secret swimming spot guarded by cliffs.

These lovely Turkish-styled baths were brought back to life after winning a reality show competition.

A perilous medieval road leading right into the sea.