Rumored to be the famed pirate's lookout tower, this historic stone structure is now just watching for tourists.

The world's second largest single-dish radio telescope, once used to contact E.T.

Stenciled handprints and wall paintings dating back 10,000 years, some of the earliest forms of cave art.

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

150 or so scrounged-up lamps, chandeliers, and lanterns light up this alley in central Athens.

Once America’s most beautiful army base, this abandoned military fort on the coast of Monterey Bay has been left to the elements.

Giant busts of 42 U.S. presidents are sitting in a field in Virginia.

This amended headstone marks the grave of a participant in one of the most successful military deceptions of all time.

A plaque commemorates the spot in the Oregon woods where the first-ever Geocache was hidden.

Surreal riveted sea forts once protected the Kent shores from German attack.

A local dialect born in the late 19th century is only spoken in this isolated California valley.

This geothermal hot spring hides beneath a slowly growing mineral dome.

Iceland's largest geothermal mud pool is a little bit haunted and a little bit dangerous.

This Italian foot path winds through the mountains via 52 individual tunnels.

A 24-hour vending machine restocked daily with homemade full-sized pecan pies.

Hundreds of hopeful gold miners came here to get rich, but only two years later the small town was deserted.

A roaring, awe-inspiring double cascade of icy water flows through woodland Oregon like something out of a Tolkien novel.

Dyed by iron oxide over centuries, these sandstone rocks rise thousands of feet into the sky.

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

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

Canyon walls shrouded in ferns.

Enormous lake at the bottom of a unique cave system.

One of the most spectacular canyons in the world.

Crystal clear lake with a shoreline of travertine located in a Colorado canyon.