A 40-foot waterfall flows into this unique natural swimming hole.

One of the deepest springs in Missouri.

An average of 33 million gallons of water pour out of the collapsed cave at the heart of this spherical spring.

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

Giant granite rocks standing end-to-end like a train of circus elephants.

In the St. Francois Mountains in the Ozarks at 1,772 feet above sea level, Taum Sauk Mountain is the highest (and possibly oldest) peak in Missouri.

Erosion and time have created a naturally-formed water park.

This restaurant serves wood-fired fare served in a natural cave with a live spring.

This futuristically sylvan church is a glass-enclosed marvel of modern architecture.

This monumental Jesus is often referred to as "Our Milk Carton With Arms."

The warmest cave in the Ozarks features two seemingly bottomless lakes.

This unassuming layer of clay boasts an out-of-this-world origin story.

Is this 47.7-mile stretch of highway the longest straight road in the United States?

An extravagant western hotel where every floor is the "ground floor."

A large stone map of Arkansas awaits visitors to its highest point.

This remote Colorado canyon is home to the second-largest collection of natural arches in the world.

It would be easy to walk past this unusual piece of art and have no idea it pays tribute to the odd life of a real chicken.

One of the world's oldest and most massive living organisms is a grove of quaking aspens.

This railroad magnate's 19th century tower is more than a little bit out of place in the Nevada desert.

Two craters, which probably erupted within the last 1,500 years and are now filled by alkaline lakes, represent Nevada's youngest known volcanic activity.

Bizarre lunar-like landscape with thousands of large stone "hoodoos."

Once a menacing challenge for trailblazers, this trail is now the most scenic drive in Utah.

This outsider art paradise is filled with dinosaur sculptures crafted from recycled machinery.

At this gas station in the middle of the desert, a convenience store has been carved directly into the rock.