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

This semi-secret storybook hedge maze is also the oldest garden in the city.

A floating cat sanctuary on an Amsterdam canal.

The largest hot spring in the United States is, as the name suggests, a stunning show of natural color.

Northern Ireland's Brobdingnagian stepping stones.

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

A walk-in working camera obscura produces 360-degree live images of the San Francisco coast.

A stunning, two-tiered waterfall made famous by poets, artists and the legend of a ghost dog.

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

Every autumn, this hillside is ablaze with red summer cypress.

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.

Ninety feet off the valley floor is an ancient dwelling put under protection of the U.S. government by Teddy Roosevelt.

An Australian lake whose pink hue defies scientific explanation.

The atmospheric road was never meant to be so creepy.

360° views of the city plus five floors of optical illusions and hands-on science.

A beautiful geyser under environmental threat.

The birthplace of an eccentric alchemist and possible inspiration for the fictional reanimator of monsters.

A 30-acre garden inspired by the principles of modern physics.

The first declared National Monument in the United States.

Just a few miles from downtown Atlanta is a trail covered in a crazy collection of outsider art.

Stroll through a wonderland of stupendous moss-covered trees.

The feral felines of Roosevelt Island have a small army of allies and an abandoned hospital all to themselves.

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

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