This secluded aqua waterfall in the Grand Canyon is the perfect swimming hole, and the Havasupai tribe's fiercely protected natural wonder.

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

The only natural lake in the world that drains into both the Atlantic and Pacific Oceans.

A haunting army of decomposing, moss-covered stuffed animals and dolls guard this swinging truss.

An abandoned railroad tunnel transformed into a creepy path for hikers and cyclists.

The tunnel that runs beneath this former inn was once a hiding place for enslaved people seeking freedom.

This museum is a full-size replica of an original church constructed during the 13th-century.

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

This overgrown Illinois water park offers a whole new type of adventure.

Scenic mount trashmore, Virginia Beach's most curious waterfront still has a couple of secrets.

This national park on the shore of Lake Michigan features remarkable dunes that lie at the heart of a Chippewa legend.

These Great Lakes sea caves accessible by boat in the summer turn into temples of ice reachable by foot in the winter.

When waves crash onto this section of beach, the rocks sing a song.

A meditative space out of a fantasy story.

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

This naturally heated mountainous creek has created a group of neon blue pools of potentially deadly boiling water.

The deepest lake in the United States, and once the site of epic destruction that lives on in legends.

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

Tour the world's largest deep-hole dimension granite quarry, where you can view the plant where gravestones are made and roll a ball down the outdoor granite bowling alley.

Bad farming practices caused this unnatural natural wonder.

This sacred cavern, 400 feet deep, is home to millions of bats and an ancient burial ground.

Mysterious rocks that ring musically when struck.

An emerald-green grotto just a short trip from Austin.

Natural rock water slides hidden in the remote forests of northern Idaho.