One of the only Florida forts to remain in the hands of the Union all through the Civil War still stands as a historic stronghold.

A stone pillar marking the location of the westernmost battle of the American Civil War only honors one side of the conflict.

The outcropping is graffitied with the name of the beloved musical Muppet television series.

Mysterious glowing orbs float through the desert night.

A Prada store in the West Texas desert that is never open for business.

Unopened beer cans are left at this monument to honor the Navy men who lost their lives during a training mission.

On October 26, 1963, a 12-kiloton nuclear device was detonated here in granite some 1,211 feet below the ground surface.

Located in the remote Monitor Valley, this travertine bowl contains a scalding pool of water.

This central Nevada cave is the spiritual home of ancient and enigmatic pictographs.

A Nevada mining boomtown that ran out of silver and luck.

Colorful outcrops and cliffs just north of Reno provide a scenic backdrop for hiking and mountain biking.

These huge stone ovens in the desert fueled the Nevada silver boom, and may have also been a hideout for outlaws.

Equipment used to mine silver and lead has been preserved in this almost-ghost town in northern Nye County.

The site of an underground detonation of a megaton nuclear bomb in the middle of the Mojave Desert.

This massive crater in the middle of nowhere was used to train astronauts for moon landings.

The liveliest ghost town in the state.

One of the most unusual geological features, recognizable from a dozen hit movies.

Millions of years of oxidation make a drive down this winding Death Valley road surprisingly colorful.

The lowest point in North America is home to an undrinkable pool surrounded by fields of geometric salt flats.

"Only the devil could play golf here."

Ten 25-foot-tall, beehive-shaped kilns, abandoned in Death Valley.

This crumbling Death Valley mining complex was known for its use of giant, 20-mule team wagons.

The rocks in this arid basin leave trails of movement behind them.

Travelers leave tea kettles in a remote part of Death Valley as part of a mysterious, decades-old tradition.