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

An arsenic-filled pool in the Grand Canyon takes on the appearance of a giant, overflowing pumpkin.

See massive fossils that are over 200 million years old in northeastern Arizona.

A self-built castle made by a mysterious man.

An abandoned facility that has become a place of ritualistic satanic worship, or so rumor has it.

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

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

Dramatic river bend surrounds a natural red-rocked pedestal.

Most-visited and most-photographed slot canyon in the American Southwest.

Rippling sand dunes frozen in the Arizona rock.

The remains of a former logging boom town, crumbled away in the forest.

Activists are fighting to preserve these unfinished highway ramps as a tribute to the citizen revolt that halted their construction decades ago.

A graveyard for early settlers, sometimes called Old Pioneer Cemetery, hidden in the woods on a hillside.

People come from across the globe to swim in this lake believed to have healing properties.

Sleep beneath the big screen at this old-school movie theater.

A magical sanctuary of mythological statuary.

A 1940s nuclear reactor built to produce plutonium for the Manhattan Project.

This inanimate goat created by the "welding nun" has been helping to clean up the city of Spokane for more than 40 years.

Nuclear reactor created the plutonium used on Nagasaki.

A frozen relic of Seattle's hydroelectric boom is now a teaching facility for future engineers.

An abandoned 19th-century hospital now swirling in ghost stories.

This grove of ghostly cedars was killed in 1700 by an enormous tsunami, felt from the United States to Japan.

From overly ambitious (and eventually abandoned) atomic dream to bustling office park.

This tiny home built on revenge appears to be scarcely wider than a Volkswagen.