Only intact Ichthyosaur skeleton in the United States.

The water in this preserved area spawns vegetation that gives it a deep green color.

This divisive system of turtle tunnels was built to save animals stranded after a highway split a lake in half.

Over a dozen Native American earth mounds dating back over 2,000 years dot this Tennessee archaeological park.

The site of the Scopes Trial contains a small exhibit dedicated to the famous case.

A massive volcanic plug is now a protected area that hosts a number of bird species.

A 300-yard long natural tunnel runs through a ridge deep in the Appalachian Mountains.

The highest peak in the state of Vermont has some interesting features.

Visit this playground of waterfalls, caves and sinkholes.

Once defending the city of New Orleans from invasion by sea, this fort faces an uncertain future.

This historic collection of Native Alaskan artifacts was resurrected through a partnership between the WPA and tribal artisans.

Aqueducts have dramatically changed this old lake, now home to tufa towers and its very own species of tiny brine shrimp.

One of the most scenic falls in Massachusetts has a history of death and grim legend.

Bad farming practices caused this unnatural natural wonder.

This mysterious and once-grand memorial still embodies a remarkable architectural vision.

This abandoned nuclear cooling tower casts a shadow over a bucolic town.

Over 12,500 words are scrawled across each room of this historic plantation house and no one knows why.

The mysterious 855-foot zigzagging stone wall has been baffling people for centuries.

Even Henry David Thoreau found this glacial pothole irresistible.

The home of pigs, snakes, chameleons, and the alleged largest bunny in the United States.

Rare recess caves fill this unbelievably beautiful Ohio park.

The remains of a boarding school designed to forcibly assimilate Native American children.

This restored opera house is named after a soprano known for tragic romance, exile, and a truly uncomfortable wedding.

In the middle of a remote desert town is a surprisingly opulent hotel.