A trio of hidden hot tubs takes advantage of Iceland's natural geothermal vents.

If a glacial river suddenly diving into a sheer chasm via a dramatic, multi-stage waterfall isn't peak Iceland, it's certainly close.

These ominous lava formations were said to be an entrance to the netherworld so of course they inspired a famous metal band.

This wrecked airplane has been sitting on a black sand beach since the 1970s.

Iceland's "Smoky Valley" is a beautiful river that is shrouded in a constant cover of steam clouds.

Strange rock formations tower above the river that snakes through this enchanting Icelandic canyon.

This fantastical waterfall is hidden in a cave located in a cracked cliff.

One of the tallest buildings in Iceland, and perhaps, the most visually impressive.

Iceland's largest lagoon is home to stunning multi-colored icebergs.

This eye-popping Icelandic crater lake is surrounded by red volcanic rock.

Rising from the sea like a stone monster.

This tiny train shuttles passengers to one of Northern Ireland's most spectacular sights.

The ruins of this medieval castle in Northern Ireland have inspired artists from C.S. Lewis to Led Zeppelin.

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.

This World War II relic let Allied pilots know they were entering neutral airspace.

This one-time health resort was used by aristocrats around the world.

The celebrated eyesore created by starry-eyed sweethearts.

How did a French journalist’s grave become the sexiest statue in the cemetery?

France's most famous cemetery, with some of its most curious tombs.

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