From Austrians to Nazis to Soviets, this historic Budapest fortress has a history as complex as the city itself.

Tucked away near more famous landmarks lies a statue meant to symbolize the confluence and continuing development of human culture.

A fake Transylvanian castle houses a cathedral of antlers.

This hidden art nouveau gem was designed by an architect in search of a national style.

What looks like a suicide in progress is actually a statue of Sigmund Freud.

The history of occult science is turned into a creepshow at this lurid Prague tourist attraction.

The hidden lair of an alchemist rediscovered in a 2002 flood.

A terrific purveyor of natural history objects and curios.

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

A tiny microvalley etched into the side of Knocknarea Mountain hides another world.

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

This 30-foot pile of rocks may be the grave of a mythological Irish queen.

A floating McDonald's built for Expo '86 is now a derelict relic on Burrard Inlet.

This Art Deco masterpiece has stood in for some of the most famous buildings in comic book history.

Antiques shop filled with all manner of curious collectibles.

This Italian-style temple replica has been threatening to fall off the Irish coast for hundreds of years.

The highest peak in Northern Ireland is topped with a stone tower and haunting burial mounds.

A rocky Irish outcropping with a history of wealth, conflict, and ruin.

Huge standing stones mark a site of megalithic mystery.

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

This floating garden in the sky is straight out of a fairy tale, but the real thing is nothing short of magical.

An abandoned horticulture institute gloomily presides over rows of derelict and vine-wrought greenhouses.

A theme park that suffered massive flooding during Katrina was abandoned, and now proves irresistible to trespassing explorers.

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