A fiery crater has been burning in the Karakum Desert since 1971.

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

A colorful architectural gem in Seattle's uniquely modern Central Library.

Northern Ireland's Brobdingnagian stepping stones.

The ghost town left by the worst nuclear disaster of all time is being taken over by nature and urban explorers.

Once the most densely populated place in the world, this island is now a ghost town.

A Jenga-style cylindrical tower of books that appears to go on forever.

Quite simply the largest tree in the world (by volume).

An ancient capital city that dates back 3,000 years old and harbors many surprises.

Tour the sci-fi-esque reality of governmental disease management.

If drivers cross the rumble strip on this stretch of Route 66 at just the right speed it plays "America the Beautiful."

This strange seaside tower got its name from a wealthy eccentric who would hide coins among its stones.

One of only two commuter aerial tramways in the United States.

A modernist landscape of water and sci-fi concrete.

Ride the subways of yesteryear.

Frank Lloyd Wright's most iconic home dangles over a Pennsylvania waterfall.

One person's lost luggage is another person's treasure.

Towering basalt columns, a creation of fire and ice.

The first declared National Monument in the United States.

A beautiful 62-acre Catholic shrine and botanical garden.

Stepping away from the glitz of mobsters and casinos to learn about the other history of Vegas.

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.

This 1,300 year old monastery built atop a single rock was once only accessible depending on the whims of the tide.

The intricate stonework of Machu Picchu serves as a testament to Incan engineers.