Designed by Buckminster Fuller, this relic of the 67 Expo survived fire and ice.

A makeshift shrine to the late rock star is still kept up on the nondescript façade outside 1 Logan Place.

Moss and stone turn this waterfall into an otherworldly liquid veil.

Railways may have forged this quintet of lovely tunnels, but now they are open to hikers.

Natural time capsule containing an alien ecosystem.

Ancient cliffs resembling a kilt on Scotland's second largest island emit an entrancing sound.

This lake in the Cascades lives up to its name, disappearing down a hole every spring.

The world's highest and most dangerous infinity pool lies at the precipice of Victoria Falls.

This expansive bridge in the Canadian wilderness was originally just built for friends.

A gargantuan crystal kingdom.

Giant, natural amphitheaters made of delicate geological formations called "hoodoos."

Walk 2,300 feet above the ground on the "Troll's Tongue."

One of the most scenic stretches of road in America winds between some of the country's oldest trees.

The hike through a narrow river flanked by the 2,000-foot-tall walls of Zion Canyon is one of the best in the world.

A seemingly endless landscape of pure salt stretches far across Bolivia.

Breathtakingly blue walls shimmer inside the "Glacier Behind the Town."

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

This frequently-photographed waterfall takes only a short hike to visit.

Take a drunken tour inside the world's largest known geode.

A museum dedicated to the alleged Roswell Incident.

Tubing through a cave lit with glowworms is a magical underground experience.

In the middle of an extremely unforgiving and desolate high desert is the most secret military facility in the world.

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

Mother Nature outdoes herself with this stunningly beautiful set of caves carved into marble.