This 19th-century ranch is being transformed into a residential library with thousands of books about the natural world.

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

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

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.

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

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

Victorian "Fancy Craft" Hair Wreaths and Relics.

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

Small teepee-like houses built for TB patients have become sheds, studios, and bus stops around Colorado Springs.

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

It's easy to forget what century it is as you wander this rustic homestead.

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

The highest paved road in North America winds its way up Mount Blue Sky in Colorado to an altitude of 14,130 feet above sea level.

Birds with backpacks expedite film development for a rafting company on a remote Colorado river.

One of the smallest towns in the United States.

Long before guestbooks and hotels, frontier travelers signed their names on this rock face.

An experimental, automotive replica of Stonehenge.

Over 600 acres of idyllic open grassland honor Nebraska’s georgic storyteller.

The two-cell building in Nebraska was briefly owned by a teenage boy and then a Hollywood dummy.

One of America's first planned communities is preserved in a state park.

A number of gruesome unsolved murders have turned this simple home into a morbid tourist trap.

A half-mile long and three stories high, this bridge over the Des Moines River Valley mimics a descent into a mine shaft.

This large midwestern cavern features impressive rock formations and an underground waterfall.