All that remains of a gigantic earth-moving machine.

This NASA test station is home to some of the world’s largest and most powerful space environment simulation facilities.

This Czar-funded, onion-domed, lavishly muraled Orthodox Church played a starring role in "The Deer Hunter."

Ghost stories surrounded this “castle,” the only structure from a huge mansion that was never built.

Funded by John D. Rockefeller, this is one of the earliest, and most beautiful, shopping arcades in America.

This lovely university observatory continues to sit abandoned since its potential savior was sent to jail for fraud.

A miniature world of concrete and stone in Springfield, Ohio.

These sub-farmland caves are home to a majestic stalactite known as the "Crystal King."

The only remnant of a small mining town is an abandoned railroad tunnel that is steeped in ghostly lore.

The largest earthwork effigy in the world.