This museum offers an actual time machine back through Colorado's past.

Castle and secret tunnel withstood a siege until its owner was killed by the Holy Roman Empire, while sitting on the toilet.

The actual model from the original "Star Trek" series is now on display at the National Air and Space Museum.

This bar hosts an ever-evolving napkin art installation devoted to an American president.

You’ve heard of bookworms, but this small sculpture at a university library may be the world’s first bookbee.

One of Savannah's oldest and most haunted cemeteries, featuring graves desecrated by Sherman's Union Army.

A miniature train-ride through Slovenia's largest cave system.

This 4,000-foot-diameter hole is touted as "the most well known, best preserved meteorite crater on Earth."

See massive fossils that are over 200 million years old in northeastern Arizona.

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

The marker offers a rare chance to be in four U.S. states at once, though there's some controversy over its geographic accuracy.

Once a lonely sentinel on the edge of the Great Plains, this rebuilt trading fort offers a glimpse of life on the Santa Fe Trail.

This super steep hike ascends 2,000 feet in less than a mile.

Strange red rock formations that have been attributed to a higher power for hundreds of years.

The largest source of fossilized insects anywhere.

The Denver airport is guarded by a 32-foot-tall sculpture of a demonic horse.

The remains of the dam that unleashed a 15-foot wall of water on Denver.