One of the most-photographed caves in the country, Stephens Gap in Alabama has a 143-foot pit, the bottom of which can only be reached with proper equipment for vertical caving — and a lot of skill. If you’re lacking in either, you can still hike to the short walk-in passage, but take caution on the steep trail.

Alabama: Stephens Gap

The best chances of experiencing the northern lights, or aurora borealis, are between August 21 and April 21 in Fairbanks, Alaska, due to the city's location under the "auroral oval" and its consistently clear skies. Bright green, teal, purple, and white lights swirl around the sky, taking on different shapes and lighting up the night.

Alaska: Northern Lights

Located in northern Arizona's Coyote Buttes, only 20 people per day are allowed to visit The Wave, a Navajo sandstone dating back to the Jurassic age. The 190 million-year-old sand dunes are calcified layers of red, yellow, brown, orange, and purple rock, worn down from centuries of runoff and wind.

Arizona: The Wave

Also known as Hawksbill Crag, Whitaker Point in Arkansas offers utterly breathtaking views of the surrounding Ozarks at an elevation of 400 feet. Hike three miles there and back on a trail that's not too difficult to trek, and you'll be surrounded by beauty, with wildflowers in the spring and gorgeous foliage in the fall.

Arkansas: Whitaker Point

Racetrack Playa is a dry lakebed located in California’s Death Valley National Park, with "sailing stones" — dolomite and syenite rocks that seemed to move on their own, leaving visible tracks behind them. Using time-lapse photography, scientists proved in 2014 that a specific balance of water, wind, and ice caused the stones to be pushed around.

California: Racetrack Playa