More than 5,000 artifacts donated by the people of the city, plus a room entirely devoted to the band U2.

Dublin's "Dead Zoo" serves as a window to Victorian museum design.

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

A moody and picturesque riverside ruin overgrown with vegetation.

One of the most popular megalithic sites in Ireland stands as a humbler version of Stonehenge.

An eccentric garden of sculptures crafted in India decorate an Irish green space dedicated to Alan Turing.

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.

An Orthodox church inside a small "Garden of Eden" built by a man who had a vision.

This unique rock formation has become a popular walking trail.

This jaw-dropping 19th-century bridge uses its reflection to form what appears to be a perfect circle.

Rainbow-hued in the summer and crystalline in the winter, this salty lake has inspired battles, temples, and plenty of awe.

Three bridges straddle a stream, one stacked upon the other.

A Welsh sheep farm provides daily (non-sheep) meals to red kites, producing dazzling displays of aerial acrobatics.

One family's environment-friendly hobbit-house in Wales.

The Stonehenge of Wales is one of the grandest neolithic dolmens still in existence.

Eerily lifelike effigies stare at everyone who enters this sanctuary.

This Scottish castle has witnessed clan rivalries, Jacobite uprisings, whisky smuggling, and more.

Staves, storm-calling, and of course, necropants.

The cell which saved the life of Ludger Sylbaris, "the man who lived through Doomsday."

The half-mile long structure is so impressive, it even shows up on satellite images.

Natural time capsule containing an alien ecosystem.

This 20-foot mountain is made up of some 15,000 mannequins—if you visit, you can even take a piece home with you.

This palatial spiral staircase was so unusual the name "snail" was given to the noble family who built it.