One of the world’s largest collections of petroglyphs records 2,000 years of human activity.

A tunnel with windows, so you don't miss out on the impressive views.

Despite its name, this route in southern Utah offers a heavenly day trip.

The fifth-longest natural arch in the world, and the longest outside China.

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

This rugged area of red rocks and arches is often considered one of the most beautiful places on Earth.

Giant, natural amphitheaters made of delicate geological formations called "hoodoos."

Here, at the "world's longest art gallery," you'll find forty miles of ancient petroglyphs and pictographs.

A memorial dedicated to the victims of the Columbine High School shootings.

A focal point of in Denver’s skyline for over a century, inspired by a Venetian basilica.

This was once the home of Gahan's Saloon, Denver's most storied speakeasy.

Air Force Academy Chapel made of 100 identical tetrahedrons works to inspire those of all religions.

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

Travel through the wholesome amusements of yesteryear at this charming miniature village.

This iconic science fiction house still looks like something from the future.

The spot in the Mile-High City that's exactly 5,280 feet above sea level (at least for now).

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

Thanks to a quirk of elevation this gift shop produces magic doughnuts that are found nowhere else on Earth.

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

The largest self-built castle in the U.S., six decades in the making.

Paranormal experiences in this hotel's room 217 led Stephen King to write "The Shining."

View the California coastline (and the home of Barbara Streisand) inch by inch with stunning, government-sanctioned aerial photography.

Sports history, made in the Arroyo Seco.

This giant spider sculpture made from the iconic car is one giant visual pun.