This natural wonder drops 16 stories straight down through rare flora and streaming waterfalls.

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

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

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

A sacred site for Native Americans surveyed by George Washington and owned by both King George III and Thomas Jefferson.

Wall Street has a new heroine, a bronze statue of a small but fierce girl.

Seattle's own bad art museum located inside Cafe Racer.

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

It's not hard to see why the historic Peabody Conservatory of Music's library has been described as a "cathedral of books."

An acoustic anomaly with a mysterious cause.

A modernist landscape of water and sci-fi concrete.

A museum dedicated to the alleged Roswell Incident.

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

Each year these high desert hills are absolutely covered with poppy flowers in a surreal show of nature.

Ride the subways of yesteryear.

This 4,000-foot-diameter hole is touted as "the most well known, best preserved meteorite crater on Earth."

A huge musical sculpture and other art installations on the National Oceanic and Atmospheric Administration grounds.

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 monument to the art of slicing people open.

An underwater city for the dead.

A hotel and restaurant serving as the mecca of kitsch.

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

A DIY art gallery/music venue/lecture hall dedicated to video game culture.

The first declared National Monument in the United States.