Huge standing stones mark a site of megalithic mystery.

While only two of the ancient buildings at this site are actually churches this was one of the earliest Irish pilgrimage sites ever.

A nun spent 16 years painting the stunning Celtic mural that covers the interior of this WWI memorial.

An Iron Age fort on the edge of a seaside cliff offers a glimpse into an ancient, mystical world.

The oldest pub in Ireland may also be the oldest surviving bar in the entire world.

An 80-year-old plane tree is devouring an iron bench at Ireland's oldest law school.

One of Ireland's most infamous prisons for rebels including men, women and children.

A museum that cashes in on its infamous little people while teaching you a thing or two about the Irish fey.

At this cozy bar tucked down a hidden Galway backroad, Guinness makes the Gaelic come out.

This Irish museum in a historic 19th century market pays tribute to the glory of butter.

The ancient tomb acts as a calendar that keeps perfect time.

This Irish show cave is said to have been the site of a Viking massacre that claimed 1,000 lives.

Perfectly preserved ancient monastery in an impossibly dramatic location on a rocky island in the Atlantic.

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

17th century streets hidden under Edinburgh were once a breeding ground for the black death.

Grab a cuppa at England's first and only domestic tea plantation.

Near the former site of numerous witch burnings, this lavish Edinburgh mainstay pays homage to Scotland's brutal history.

The world's first underground farm is in a World War II bomb shelter beneath the streets of London.

These fantastically named natural pools look like something out of a Scottish myth.

The mysterious, fantastical woodland inspiration for "The Lord of the Rings."

One of the few remaining casualties of the London Blitz, this destroyed church has become an enchanting public garden.

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

London's creepiest cemetery was once the site of dueling magicians and mobs of stake-carrying vampire hunters.

This disused Cold War bunker has been restored to all of its early 60s glory.