Giant busts of 42 U.S. presidents are sitting in a field in Virginia.

A self-built castle made by a mysterious man.

A breathtaking array of ancient Pueblo structures and artifacts counterintuitively preserved by neglect.

A castle that was built stone by stone by an eccentric journalist.

Hidden in Central Park's Ramble is a troublesome cave buried just beneath the surface.

This frequently-photographed waterfall takes only a short hike to visit.

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

Seemingly grown on some other world, these New Mexico rock formations look like a disused science fiction set.

Panorama exhibition hall in old silent theater with a beautiful backyard garden.

The longest continuous lava tube in the continental U.S. offers 2.5 miles of dark explorations for the adventurous.

Collapsing castle on the Hudson river was once the storage site of military surplus business.

An underwater city for the dead.

This strange seaside tower got its name from a wealthy eccentric who would hide coins among its stones.

A stunning, two-tiered waterfall made famous by poets, artists and the legend of a ghost dog.

A "gravitational anomaly" located in the redwood forests just outside of Santa Cruz, California.

A heavenly experience, right here on Terra Firma.

An underground mansion with fruit-bearing trees and grapes growing beneath the surface of central California.

A beautiful geyser under environmental threat.

Philadelphia boasts one of the best — and most often overlooked — traditional Japanese gardens in North America.

The first declared National Monument in the United States.

Possibly the most beautiful carillon in the world, set atop Iron Mountain in Florida.

Relics of the 1894 Midwinter Exposition continue to delight visitors today.

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

Hellam Township is reputed to feature seven remote gates, which when passed through in the right order, open an entrance to hell.