Centuries of crashing waves carved out this small hole in the rock, which lights up at certain parts of the year.

This lonesome Monterey cypress has survived centuries of wind, salt, and at least one attempt at arson.

In which a local geological marvel becomes a quaint roadside attraction.

See massive fossils that are over 200 million years old in northeastern Arizona.

Where the famed daredevil attempted to launch himself across a canyon in a custom-built rocket.

The illuminated falls are a gem in North Cascades National Park.

The world's longest known cave system.

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

Strange red rock formations that have been attributed to a higher power for hundreds of years.

Shoreline strewn with the remains of ghostly fallen trees.

This angular Dwarven tunnel cuts through a mountainside in Glacier National Park.

The only road through the heart of Glacier National Park.

The first declared National Monument in the United States.

Dedicated to the history of the 1,000 nuclear missiles that once covered the Great Plains.

One of the first intercontinental ballistic missile sites in the United States.

This stretch of beach along California's central coast is a busy highway for the largest seal in the northern hemisphere.

The only diamond mine in the world where you can keep what you find.

High in the Sacramento Mountains, a facility dedicated to studying the sun.

Explore the largest pure gypsum deposit in the world, and go dune sledding while you're at it.

Often referred to as the largest spring in America.

Thousands of unique minerals, including some of the most impressive fluorite crystals in the world.

An enormous natural sandstone bridge in Kentucky.

In the Shawnee National Forest, amazing rock formations peer through the treeline.

A chilling disappearance (and rescue) of a child uncovers a geological mystery.