The most powerful laboratory radiation source in the world pulses with 1,000 times the electricity of a lightning bolt.

The 7,000-year-old calcium carbonate formation creates a magnificent natural bridge.

On the edge of the Valles Caldera National Preserve, these rock formations create an eerie landscape.

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

This museum started as a collection of Manhattan Projects and continues to add exhibits as they are declassified.

A half-mile long and three stories high, this bridge over the Des Moines River Valley mimics a descent into a mine shaft.

Beating out all other concrete competitors, this massive garden feature's pointy hat has earned it a world record.

A single artist is behind these large-scale models made of hundreds of thousands of two-inch wooden matchsticks.

An eclectic assortment of medieval architecture in a small Iowa town.