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

The haunted reputation of these abandoned Colorado train tunnels is probably not helped by the terrifying spiked fence.

Ninety feet off the valley floor is an ancient dwelling put under protection of the U.S. government by Teddy Roosevelt.

This small piece of railroad history sits behind the parking lot of a chain grocery store.

This statue of an obscure comic strip hero stands as a tribute to patriotic service and a cautionary tale about embracing fads.

A seven-story 1920s mausoleum outside Denver houses thousands of remains.

A prehistoric rock shelter that's literally in someone's backyard.

In the middle of a suburban Denver neighborhood is a cave that once provided solace for a prominent Ute chief and his family.

Open-air cremations in Colorado's self-proclaimed spiritual mecca.

The burial grounds of a secret society includes fences topped with fake Tesla balls.

The remains of an early 1900s dude ranch that operated until the 1970s.

This eclectic collection documents the wild legacies of "America's Wickedest Street."

The wreckage of a World War II bomber is hidden high in the Colorado wilderness.

An enthusiastically interactive mining museum that won't let black lung ruin the fun.

This grand stone tower was dedicated to a famed American humorist almost by coincidence.

A fake mine that was made using real mining techniques which is also used as a community center.

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

This deserted Gold Rush town is home to a Masonic lodge that, strangely enough, still holds meetings.

The largest dinosaur trackway in North America is tucked away among this canyon's ghosts and archaeological gems.

One of the greatest heroes of the Titanic tragedy came from humble beginnings to this beautiful home.

The moving metal works of one troubled artist can still be viewed on his front lawn... for now.

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

The final resting place of American icon Buffalo Bill, and a museum that aids in telling his tale.

One of the largest Buddhist stupas in North America is built of concrete designed to last 1,000 years.