This large cave is a summer home to thousands of bats and has a rich history dating back to prehistoric times.

The mysterious wonder of an underground waterfall is illuminated by multicolored lights.

Like Mars, but much closer.

148 feet long and in the middle of a verdant forest.

These strange large stones served as a campsite and lookout post for generations of Native Americans.

Constant erosion has created a surreal landscape of bleached and preserved fallen trees.

Mile-long cave system near Great Smoky Mountains.

A humid oasis combines recreation with exploration in a unique underwater cavern.

One of the oldest living oak trees in the Southeast.

This granite rock face is named for the magnificent reflection that occurs when the sun hits it just right.

The only Florida state park with publicly accessible caves.

The perfectly named cave drop is the deepest in the continental United States, almost matching the height of Seattle’s Space Needle.

A once-groundbreaking power plant turned into a hotel and mini-museum of archeological and geological wonders.

One of almost 200 confirmed impact craters in the entire world, untouched for tens of millions of years.

A curious whirlpool formation supposedly capable of entangling or engulfing branches, tree trunks, or whole rafts full of hapless tourists.

Incredible miniature towns and buildings created and decorated with thousands of tiny rocks.

Bad farming practices caused this unnatural natural wonder.

A little-known mural reveals the hydrological reason for Atlanta's founding in this location.

This hidden stone has absorbed decades of human anxiety.

The only ancient owl carving found east of the Mississippi.

An enormous goose sits atop this nest-shaped home.

Come for the boats, stay to explore the intriguing assortment of art.

Dinosaurs invade a suburban Nashville neighborhood.

In Florida, these naughty monkeys live on their own mini-monkey Alcatraz.