This ancient abbey now lies in majestic ruin behind a caravan park.

The longest and tallest aqueduct in Britain can actually be sailed across.

Largest lake in Great Britain measured by surface area.

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

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.

Famously misunderstood wonder of the ancient world

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

One of the few standing Roman lighthouses and a labyrinth of tunnels are a couple of the secrets at this historic castle.

A granite plane marks the site where a French aviator completed the first airplane flight across the English channel.

This castle resides in a valley known for immense bloodshed during the Middle Ages.

A series of idealized caves carved to entertain guests.

Legends say this red sandstone monolith and the dozens of smaller boulders that surround it were once a coven of witches—before a Scottish wizard turned them all to stone.

An impressive Neolithic henge with banks nearly 10 feet high.

Though this large circular site is now named for the legendary king, its history dates back to the Neolithic era.

The abandoned railway bridge stands hidden in the farmland of rural Cumbria.

This amazing trail among the many waterfalls around Ingleton has been enchanting visitors since 1885.

Locals spent years successfully fighting to save this beloved Brutalist behemoth from demolition.

A harrowing sculpture commemorates the four people shot down during the workers strike of 1842.

This hospital once pioneered the use of electroencephalograms, but fell into maltreatment, abuse, and eventual abandonment.

This 20th-century replica of a 13th-century castle has itself fallen into ruin.

A miniature Italianate fantasy village on the coast of Wales and the set of ITC classic "The Prisoner."

The oldest continual pilgrimage site in Britain was supposedly created by a gruesome beheading.

A geological wonder shrouded in myth.