The vast, legendary catacombs hold secrets much stranger than stacked bones.

Islanders once used this dramatic, otherworldly landscape to hide their cattle from Viking raiders.

The heart of a Scottish legend had a centuries-long journey before reaching its final resting place.

Overlooked by many, the two famous Scottish warriors guard the main gate of Edinburgh Castle.

This macabre monument atop an ancient well gives a nod to a brutal episode in Scottish clan history.

The most loyal of little dogs, or a Victorian era publicity stunt?

The final resting place of soldiers' loyal canine companions.

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

Largest lake in Great Britain measured by surface area.

The highest peak in the United Kingdom has a history of physics, specters, and a pilgrimage of strange objects.

A church that bred legends, and served as an inspiration for the Da Vinci Code.

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

360° views of the city plus five floors of optical illusions and hands-on science.

A 30-acre garden inspired by the principles of modern physics.

Ruined 11th century abbey built by King David I in Edinburgh, Scotland.

This 17th-century street hidden beneath Edinburgh was once a breeding ground for the black death.

This astonishingly geometric cave has inspired everyone from Jules Verne to Pink Floyd.

A museum marks and documents the site of the Titanic's launch.

This short bridge is the only thing connecting a tiny Irish island to the mainland.

Northern Ireland's Brobdingnagian stepping stones.

The atmospheric road was never meant to be so creepy.

A particularly disconcerting tribute to Irish martyrs.

This controversial Irish show cave is home to a massive formation known as the Great Stalactite.

A remarkably intact castle that once was the largest in Ireland.