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

The last holdout of a pre-Civil War rebel who took the matter of slavery into his own hands.

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

Take a steam-powered ride straight out of the past on this Appalachian rail line.

Berkeley Hot Springs presents to you "the only outdoor monument to presidential bathing."

One day a year it is legal to jump off of this astoundingly tall bridge that spans an Appalachian gorge.

Four hundred granite steps were built into this massive rock by the National Park Service.

Standing in a state of "arrested decay," this ghost town allows for a detailed peek into Gold Rush life in an unusually harsh climate.

Aqueducts have dramatically changed this old lake, now home to tufa towers and its very own species of tiny brine shrimp.

Quite simply the largest tree in the world (by volume).

San Francisco's newly reopened hands-on science museum.

In all of the 29 years it was in operation, no prisoners ever escaped successfully... or so they claim.

These unusual rooms on wheels are holdovers from the 1960s.

At Washington's Dulles Airport is a satellite museum (no pun intended) with three quarters of a million square feet of aircraft history.

Herbert Hoover's "Brown House" rural presidential retreat was a PR disaster amid the start of the Great Depression.

This pre-Revolutionary War grist mill ground corn and flour for soldiers in seven American wars.

Outsider art meets paleontology at this roadside reptile repository.

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

The Pennsylvania shopping center was once the setting for the 1978 film, "Dawn of the Dead."

This public space is speckled with the eerie remnants of a defunct amusement park.

"Where the ducks walk on fish."

Where the oil industry began.

Could it have picked a better place to land?

This dramatic rail curve was once the target of a failed Nazi attack.