At the time of its completion, it was the tallest dam in the world.

A small town built on an abandoned airfield has former runways as streets and a bar and grill in an old airplane hangar.

Creek water that starts here has a 50/50 chance of ending up in the Atlantic or the Pacific.

Devilish landscape, once cinema home to giant alien bugs, now derelict roadside attraction.

An architect's childhood fantasy treehouse made real.

Native Americans built this circle of stones, which was used to predict astronomical events.

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

One man's ambition created this psychedelic log home.

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.

The first declared National Monument in the United States.

A historic estate packed with George Washington's heirlooms, and its own nuclear bunker.

The highest point in Washington state is a volcano covered in glaciers.

This former coal gasification plant found a curious second life as a popular public park.

An extraordinary mixture of natural beauty and man-made phenomena.

The longest continuous lava tube in the continental U.S. offers 2.5 miles of dark explorations for the adventurous.

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

A walk through the historic city center, under the streets of Seattle.

This charming woodland trail is peppered with poetry.

Two distinctive homes on a New England village green look like a couple of frosted wedding cakes.

A dazzling display of red rocks weathered into spires and hoodoos.

A small oasis not far from downtown Moab.

The fifth-longest natural arch in the world, and the longest outside China.

Giant pinnacles in the sun-scorched lands of Southern Utah have been nicknamed "white ghosts."