The former "holiday home" for monks at the Durham Cathedral.

The longest staircase lock in Britain.

A close look reveals that the Scottish monument is just slightly off-kilter.

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

Unusually, this ancient Iron Age broch has never been excavated.

A castle in the Scottish Highlands has been continuously inhabited since the 1300s.

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

The discovery of this Neolithic settlement, which contained a Stone Age "cathedral," threw archaeologists for a loop.

The true age of this ancient stone circle is unknown, but its stunning vista isn't in question.

Possibly the oldest of Britain's ancient henges is also one of its most stark.

Thanks to both terrific preservation and historic vandalism this ancient site is known as the "Heart of Neolithic Orkney."

Enter the world under the hill at this ancient UK burial chamber.

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

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

This tin chapel was built by POW's during World War II and is painted to look like something much more grand.

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

A collection of short standing stones covers this hillside.

The sign marks one of the endpoints to mainland Britain's longest overland travel route.

A red-brick beacon stands against the tempestuous Atlantic, on the windiest site in the United Kingdom.

A remarkably well preserved tower dating all the way back to the Iron Age.

Gothic tower where Lord Alfred Tennyson wrote the poem "The Sleeping Beauty."

Mysteriously stacked storefront paths give this medieval British town an iconic style like none other.

This sculpture of Edward of Woodstock is surrounded by eight Victorian lamp bearers.

Britain's tallest megalith towers over the cemetery of a quiet English village.