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

This unique structure in suburban Austin is made up entirely of other people's castaways, and constantly changing.

Carnivorous plants, medieval aphrodisiacs, and the largest original wood structure glass conservatory in the western hemisphere.

Aqueducts have dramatically changed this old lake, now home to tufa towers and its very own species of tiny brine shrimp.

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

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

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

Hollowed out cedar log tubs set in an ancient towering forest.

Home to items never before seen by the public.

Possibly the most beautiful carillon in the world, set atop Iron Mountain in Florida.

A beautiful geyser under environmental threat.

The deepest lake in the United States, and once the site of epic destruction that lives on in legends.

Here, at the "world's longest art gallery," you'll find forty miles of ancient petroglyphs and pictographs.

One of the world's oldest and most massive living organisms is a grove of quaking aspens.

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

Mysterious rocks that ring musically when struck.

The first declared National Monument in the United States.

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

Stroll through a wonderland of stupendous moss-covered trees.

This secluded aqua waterfall in the Grand Canyon is the perfect swimming hole, and the Havasupai tribe's fiercely protected natural wonder.

Enormous lake at the bottom of a unique cave system.

The installation’s official name, “You Who Are Getting Obliterated in the Dancing Swarm of Fireflies,” says it all.

A giant Troll lurks under one of Seattle's oldest bridges.

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