These massive concrete balls were used to mine gold in Virginia.

A collection of vehicles across American military history.

The Cadillac Ranch for monster truck aficionados.

The only known Futuro house in North Carolina sits along a stretch of desolate highway on the Outer Banks.  .

The North Carolina grounds are leased in perpetuity to the British Commonwealth for as long as the WWII sailors are buried there.

More than a century old, this trading post resides in the Navajo Nation.

The Cold War-era "underground Pentagon" is a sprawling subterranean hideaway for the Defense Department.

Tour the dark and beloved poet's former cobwebbed basement, which may have inspired "The Black Cat."

A classic gold rush hotel can be expected to pick up some ghosts along the way, and the Golden North is no exception.

The facade of this relic from the Klondike gold rush is decorated with over 8,800 pieces of driftwood.

A secretive collection featuring objects that were designed specifically for U.S. intelligence operations.

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.

Outsider art meets paleontology at this roadside reptile repository.

At 207 feet, one of the world's longest continuous escalators.

This museum devoted to the gothic author holds such interesting ephemera as his socks and walking stick.

An organ located deep within a cave, whose "pipes" are the geological features of the cave itself.

The resting place of a Civil War celebrity's amputated limb.

This war hero's old shop remembers the fine line between medicine and quackery during the Revolutionary War.

The Kirkland Monument remembers a selfless Civil War hero who braved the battlefield to give water to his dying enemies.