This Boeing KC-97 tanker is now a restaurant for aviation lovers.

This three-mile concrete levee in Pueblo, Colorado was transformed into the world’s longest painting.

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

The clock that sets them all.

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

Once a mortuary that held the remains of Buffalo Bill, this Denver hotspot is now a death-fixated restaurant.

At this Denver landmark, the meals are compulsory, the sopapillas are complimentary, and the insanity is everywhere.

This naturally-sourced hot spring is now home to a clothing-optional resort.

The oldest operating cemetery in Denver is the eternal home of some of the Centennial State's most famous residents.

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

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

A technicolor place of worship for Elevationists.

Curios, scientific antiques, oddities for sale.

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

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

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

While most of the games in this arcade take quarters, that would have been a small fortune when they were made.

There are eight natural springs around town, each with a slightly different taste.

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

Hidden beyond a kitschy giant beetle is this remarkably sprawling collection of preserved insects.

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

The superstar of Cold War nuclear bunkers has been featured in countless films but is now barely operational.

One of few remaining antique carousels with stationary animals in the U.S.

A suspended garden, now gone, once hung in the middle of this abandoned church.