A 30-mile-long glacially-carved canyon leads to a massive pair of glaciers.

This fast-food outlet is the only space and UFO-themed McDonalds in the world.

The second-largest cave chamber in the world was discovered in 1898 by a 16-year-old and a friend known as "Pothead."

A Prada store in the West Texas desert that is never open for business.

When ecosystems collide in the arid Southwest.

Explore the largest pure gypsum deposit in the world, and go dune sledding while you're at it.

Ice cream stand, snack bar, and time capsule of milk conveyance.

The ancient dwellings of the Puebloans, located in the cliffs of majestic mesas.

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

A black sand beach where glacial fragments wash ashore and look like sparkling diamonds.

This functioning mill was built in the 1970s using parts from several other West Virginia mills.

The world's largest fully steerable radio telescope.

These towering spires and glowing walls are carefully crafted from hundreds of thousands of icicles.

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

Every fall this lake mysteriously drains, like a bathtub with the plug pulled out.

A surviving remnant of the thick ice mass that once mantled most of Western Canada's mountains.

Fossils, railroads, and waterfalls!

Northern Ireland's Brobdingnagian stepping stones.

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

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

An abandoned faux-pub made famous by a Guinness commercial.

The highest point in Washington state is a volcano covered in glaciers.

America's greatest forgotten garden and the former stomping grounds of Son of Sam.

In the power of this waterfall, Alexander Hamilton saw the potential for industry.