Other-worldly rock formations and ancient fossils abound in this unique stretch of Nebraska badlands.

An impressive waterfall nestled in the cliffs of Idaho's Snake River Canyon.

The 7,000-year-old calcium carbonate formation creates a magnificent natural bridge.

This highest peak in New Mexico is named after an explorer who had a habit of lending his monicker to peaks.

Some of the oldest exposed rock formations in the United States.

Marking the spot where a conquistador gave up his search for the fabled Seven Cities of Gold.

This Civil War monument was designed by an eccentric architect and Gettysburg veteran.

A wonderland of caves in eastern Iowa.

The original span of a high bridge across the deep Crooked River Gorge has been preserved for pedestrian use.

Two gushing waterfalls of hot spring water within a block of each other.

See 150 million-year-old dinosaur tracks and bones dating back to the Jurassic period.

The only bridge in the United States where BASE jumping is legal without a permit year-round.

A stretch of highway even lonelier than the so-called "Loneliest Road in America."

A colossal concrete penguin announces this Montana town as the coldest spot in America. But is it really?

A copy of the famous bus used during the filming of 'Into the Wild' is on display at an Alaska brewery.

A tunnel that brings more than a century of history to life from the deepest parts of the Niagara Gorge.

This frequently-photographed waterfall takes only a short hike to visit.

The lush coastal city of Astoria is riddled with forgotten secret sidewalks.

The second largest waterfall by volume in the U.S., Willamette Falls is outdone only by Niagara in the amount of water that is pushed northward.

This strange hill on Old Fort Road where gravity works in reverse has been fascinating locals for years.

According to legend, you must remain completely silent while passing this man-made mound or suffer the consequences.

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

A pair of large white marble lions guard this stretch of the Mojave Desert, and it is utterly mysterious how they got there.

The ghost town that ended up on Ebay.