This neolithic stone grave has been altered and restored so often its now more neo than lithic.

Picturesque ruins once held off mighty armies.

The world's largest prehistoric copper mine had 30,000 animal bones scattered throughout the maze of passageways.

A spiral staircase connects the limestone cave with Pembroke Castle, birthplace of King Henry VII.

This lonely cast-iron structure is the only wave-washed lighthouse of its kind left in all of Britain.

One family's environment-friendly hobbit-house in Wales.

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

High Victorian fantasy created a fairytale castle out of a ruined fortress in Wales.

The stately remains of Llywelyn the Great's mighty fortress.

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

This abandoned asylum in Wales might look haunted, but it's still beautiful.

The Titanic sails again in one Scotland man's backyard.

Stay in the one time home to one of Scotland's most notorious gentleman's sex clubs.

This ruined travelers shelter sits abandoned in a desolate bog of Flow Country.

Legends surrounding this megalithic tomb range from giants to a dwarf named Trollid.

This short white tower is all that's left of Scotland's first permanently manned lighthouse.

The ruins of a defunct limestone quarry still haunt this Scottish promontory.

This rare surviving broch is one of Scotland's most impressive Bronze Age structures.

A historic shipbuilding town is home to a sail-through fish-and-chips shop.

The remains of an anti-aircraft battery from World War II look out over Glasgow.

A carved bench marks the Scottish cave that inspired the classic adventure novel "Treasure Island."

This 16th-century close preserves an unusual piece of Edinburgh's transportation history.

Many of Edinburgh's more unsavory characters spent their final days behind this door while awaiting their executions.

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