A swimming hole in the historic industrial quarry that supplied the marble for the Baltimore Washington Monument.

This abandoned sea fort has become an accidental bird sanctuary.

Ship skeletons haunt Baltimore's waterways.

A winding district gerrymandered into the shape of a mantis.

This lovely tree was a thank you gift from the man known as "Public Enemy No.1."

An abandoned church gets a second life as a massive beer hall and event space.

Oldest building in California still in use.

The oldest platform carousel built in the United States continues to delight children in Martha’s Vineyard.

This candy-colored storybook village originated as a 19th-century Methodist campground.

The filming location of a shark attack in Steven Spielberg's famous shark movie.

Colorful clay cliffs tower over an unofficial nudist beach on Martha's Vineyard.

Hidden inside this Arizona fast food franchise is an in-depth exhibit on the famed WWII counterintelligence program.

The graffiti-covered ruins of an abandoned trading post in the middle of the Navajo Nation.

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

Once a dining hall for boarding school students, this lodge was a popular haunt for nuclear physicists working on the Manhattan Project.

A small metropolis of Pueblo cave dwellings have been carved right into the hillside of this national monument.

These aggressively sustainable art homes look like something out of 1970's science fiction.

A sprawling collection of over 106,000 toys from around the world.

Wedding chapel's mysterious spiral staircase said to be miraculously constructed.

The striking and little-touristed ruins of an ancient city destroyed and rebuilt by the Aztecs.

This popular pilgrimage site offers a hole filled with holy healing dirt.

This sculpture perfectly models the molecular structure of a drug that was never produced.

A natural formation that resembles a camel resting in the New Mexico desert.

An immersive environment that is part haunted house, part choose-your-own-adventure, and part jungle gym.