A Wild West jailhouse that slid down the mountainside.

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

This giant temperature attraction created some giant electric bills.

A cave's rare beauty held a cavernous secret hidden underground.

Twenty-seven massive radio antennas on the high plains of New Mexico search for life on other planets.

A one-of-a-kind sundial at the Very Large Array honors a radio astronomy pioneer, incorporating the original piers from his breakthrough radio telescope.

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

The winter home of thousands of beautiful snow geese and sandhill cranes.

This small piece of railroad history sits behind the parking lot of a chain grocery store.

The ruins of a town wiped out by the second-largest earthquake in recorded history.

Surrounded by a hundred mile radius of billboards, Little America is a roadside attraction whose primary appeal is hospitality.

400 million-year old limestone caverns nestled in the Ozarks served as shelter and a hideout for cultures throughout North American history.

A Cold War atomic camp buried under the ice is now emerging because of global warming.

A trading post in the North Pole where children send letters.

The king of U.S. high points towers over every other peak on the continent.

A suburban street in Anchorage doubles as a runway, and each home has its own airplane hangar.

An abandoned aircraft sits submerged in a lake in the Alaska wilderness.

Roadside collection of 65,000 signs.

Part of a secret 1970s nuclear defense program is now open to the public.

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

A beautiful geyser under environmental threat.

An architect's childhood fantasy treehouse made real.

One of nature's most well-scheduled phenomenons resides in Wyoming's Yellowstone National Park.

This Yellowstone geyser may not shoot as high as the nearby Old Faithful, but it erupts for considerably longer.