The highest point in Tennessee, Clingmans Dome bears witness to the ravages of one type of insect.

You can climb to the summit of Black Mountain, as long as you sign the waiver.

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

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

Bizarre lunar-like landscape with thousands of large stone "hoodoos."

"Dark Sky Park" is heaven on Earth for astronomers, one of the rare U.S. locations with no artificial light pollution.

Neither Spanish settlers nor anyone since has been able to tell who built these strange California rock walls.

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

Not truly a ship nor a building, the Navy's first and last "landship" is now abandoned due to clerical issues.

Supposedly Satanic numbers adorn this preserved submarine sail.

A shape-shifting buy-sell-trade bookstore, born to Beatnik Era spirit.

"The Most Boring Road in the State."

The largest ancient burial mound in Ohio.

Display that gathers the basic elements of the universe in one convenient location.

Limestone caves with spectacular showcase chambers.

The seamy, underground secrets of Portland's criminal past.

The fifth-longest suspension bridge the world, connecting one Michigan peninsula to another.

Final resting place of Geronimo, Quanah Parker, and the first atomic gun ever fired.

Interactive modern and vintage submarine equipment, World War II relics, and submarine attire.

Experience a charming 1930's version of "infotainment."

Water of undetermined depth has attracted rare fish and cult leaders alike.

Oddly shaped rock formation, misassociated with a nearby utopian community.

The largest dune field in the Mojave offers a chance of hearing the 'singing sands.'

This former rail stop in Utah was abandoned, repopulated by some nostalgic friends, and now is home to a single DIY aviator who lives in a hangar.