A 6th-century stone lies at the site of the mythical battle waged between King Arthur and his nemesis Mordred.

The remains of the wrecked steam trawler can be found on the beach at low tide.

This former World War II torpedo testing location is now an important nesting site for migratory birds.

This village provides a glimpse at rural life in Northern Ireland during the mid-20th-century.

Hidden in Carnfunnock Country Park is a lasting testament to the Normans who once settled in the region.

A Victorian marvel of engineering is now a 21st-century tourist attraction.

This mysterious Bronze Age standing stone has become a place where couples profess their love.

This tiny train shuttles passengers to one of Northern Ireland's most spectacular sights.

This gnarled old tree supposedly sprouted from seeds kept in the pocket of a 16th-century Spanish sailor.

A meandering boardwalk across the bogland leads to a "stairway to heaven" with sublime views.

There's a labyrinth of manmade tunnels stretching for over an acre beneath Bristol.

A medieval cave used to shelter local hermits now holds nearly 200 old Quaker gravestones.

The abandoned funicular tunnel was a secret base for the BBC during World War II.

This former World War II artillery defense site was built to guard the industrial city of Glasgow.

This astronomically-aligned stone circle was the first of its kind to be built in Great Britain after a 3,000-year hiatus.

Climb this overlooked gem's spiral staircase and you'll be rewarded with spectacular views of Glasgow.

The elaborate clockwork contraptions in this Scottish gallery create small worlds of whimsy and horror.

Hidden in a Scotland museum is a copse of extinct tree stumps.

These trenches were used to train the Scottish military for life on the frontlines of World War I.

The remnants of a facade from a 19th-century market stall emporium.

This former train tunnel is filled with lines from a poem crafted by Robert Louis Stevenson.

The last remaining bottle-shaped kilns in Scotland stand alone in an Edinburgh suburb.

The building where Mary, Queen of Scots was said to have bathed in white wine.

This alley off Edinburgh's Royal Mile contains remnants of the city's seedier history.