A downtown park built on top of unclaimed graves.

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

When zealous marijuana enthusiasts kept stealing the "Mile 420" highway marker, the State of Colorado got creative.

This spectacular track has run continuously since 1882.

The scene of one of the darkest moments in American labor history has been left essentially untouched since the tragedy.

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

At the tallest peak in Colorado, an electrifying mix of thin air, lightning, and rivalry.

The largest source of fossilized insects anywhere.

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

A little-known hot spring haven right below the highway.

These faux-cliff dwellings allow visitors to climb around on a replica archaeological site.

Abandoned silver mine strewn with wrecked and twisted structures.

This Colorado hiking trail provides a small gold mine of abandoned gold mines.

The highest bridge in America was built for an almost unnervingly small amount of money.

Hidden beneath a bridge, this waterfall is known for the large amounts of graffiti painted on its base.

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

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

This "zoo" is a cross between a junkyard and a sculpture garden, featuring animals you won't see anywhere else.

A breathtaking array of ancient Pueblo structures and artifacts counterintuitively preserved by neglect.

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

The ancient dwellings of the Puebloans, located in the cliffs of majestic mesas.

Crystal clear lake with a shoreline of travertine located in a Colorado canyon.

Wondrous sandstone hoodoos where Native Americans collected clay for pottery, 9,000 years ago.

A subterranean haunt where wine and homemade biscottis are always on the menu.