Explore the largest pure gypsum deposit in the world, and go dune sledding while you're at it.

This tiny museum's sizable collection is jammed into a former underground public toilet.

Pyramid home to an obscure religious group that practices modern mummification.

This giant ice cream cone is the last remaining icon of a Salt Lake City staple.

America's post-nuclear-attack chambers of Congress.

Near-constant high winds deform the trees on Spruce Knob, the highest point in West Virginia.

A bunker "with enough U.S. currency to replenish the cash supply east of the Mississippi" in the event of nuclear war now protects nitrate film.

The ruins of this Thomas-Jefferson-designed mansion have been left to crumble since the Christmas Day they burnt down.

A mine fire has been burning under the deserted town since 1962, but this church is still going strong.

Giant money stones of Yap.

An isolated dive site teeming with cnidarians.

The only natural lake in the world that drains into both the Atlantic and Pacific Oceans.

An architect's childhood fantasy treehouse made real.

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

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 oldest restaurant in Portland serves fiery coffee cocktails and an astounding amount of turkey.

One of the most comprehensive collections of historic Native American culture in the country reframes artifacts as artwork.

This public art piece proves that in Portland even reporting the weather is a thing of whimsy.

Amid the sprawling Defense Intelligence Agency Headquarters is one of Washington's least accessible museums.

A historic ruin just 20 feet away from a busy highway onramp.

One of the largest artillery pieces in the world sits in a Washington D.C. parking lot.

The "lovely red Vega" of the legendary record-settling pilot.

A traveling postal dog covered 48 states and more than 140,000 miles, and he lives on as taxidermy, patched up with a rabbit's foot and a pig's ear.