These Pre-Columbian petroglyphs contain representations of birds, deer, hunters, and even some early Native flute players.

A phenomenal assembly of pueblos in New Mexico is the most complete example of ancient ruins north of the border.

Eat like pre-Columbian Native Americans in this New Mexico restaurant within the Indian Pueblo Cultural Center.

A clear blue swimming hole with hidden caves, still unexplored.

The second-largest cave chamber in the world was discovered in 1898 by a 16-year-old and a friend known as "Pothead."

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

One man has carved a number of natural New Mexico caves into psychedelic sandstone temples.

The land is full of geologic eye candy, such as otherworldly spires, mushroom-shaped hoodoos, and prehistoric fossils.

One of the most extensive and well-preserved collections of dinosaur footprints in North America.

More than 350 million years ago, western New York was covered in a vast sea. Today, you can dig up the remains of the plants and animals that lived there.

The largest burial mound in the United States holds the remains of prehistoric West Virginians.

Construction uncovered this trove of fossils, which visitors are welcome to add to their own collections.

The lasting remains of the region's once booming cement industry.

The last funhouse of its kind, where guests enter through the mouth of an 80-year-old blue whale.

A smaller model of the Da Vinci sculpture that took 500 years to come to life.

The oldest continually operating golf course in the United States.

Catch a ride through the Pennsylvania countryside on this historic narrow-gauge railroad.

Hidden in the hills of Western Pennsylvania lies one of the best-kept ghost towns in America that you can legally visit.

The slate extracted from these Pennsylvania quarries was once hailed as the finest in the world.

An industrial waste tourist attraction.

These hooded graves are the only of their kind in the United States.

The site of America's first commercial oil well essentially disappeared after the town went bust.

A "house to which to flee" for settlers in colonial Pennsylvania.

Overshadowed by quilts, the artistry of these patterned textiles went underappreciated for too long.