Scotland's oldest medieval bridge is also among the last reminders of early medieval Aberdeen.

Legend says this cave housed a 16th-century cannibal and his family of 48.

Overlooking a Scottish loch, this beautifully crumbling castle once inspired a poem by William Wordsworth.

This castle was established by the 4th Duke of Montrose and is connected to the Buchanan Clan.

The mystery of this small, brick pond eluded its possibly only investigator until his death.

The ruins of this gorgeous clifftop castle look like something from a fantasy novel.

A Scottish manor with a history of mysterious fires, magic, and eccentric tales

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

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

These haunting ruins belong to an ancient village that once had one hell of a view.

Legends say that this small island was the final resting place of the Welsh saint of lovers.

The atmospheric road was never meant to be so creepy.

Just another ancient, mysterious Irish stone circle.

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

This singular Irish dolmen is more Frank Lloyd Wright than upright stonehenge.

The ruins of an 800-year-old monastery boasts the tallest round tower in Ireland.

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

Huge standing stones mark a site of megalithic mystery.

This ancient Irish religious site is covered in ancient carvings, many of which have barely aged.

There might not be much left of these Irish ruins, but their linguistic legacy is still going strong.

This courtly monument celebrates an influential comedian who turned taking the piss out of the powers-that-be into an art.

The gorgeous library at Trinity College is home to remarkable treasures of Irish identity.

The oldest public library in Ireland.

An Irish church where an 800-year-old mummy is reaching out of his coffin as if to shake hands.