A century-old cabin off of Highway 30 touts an unusual construction material: dinosaur bones.

A beautiful geyser under environmental threat.

The largest hot spring in the United States is, as the name suggests, a stunning show of natural color.

Native Americans built this circle of stones, which was used to predict astronomical events.

An architect's childhood fantasy treehouse made real.

One man's ambition created this psychedelic log home.

The first declared National Monument in the United States.

A museum, walk-through diorama, and library nestled under one castle-like roof.

Despite repeated attempts to make it work, this former mining town is now nothing but dust and memories.

A waterfall 600 ft. inside a mountain, once the bane of gold miners, is now a spectacle of nature.

This Wild West attraction is alive with glitching automatons.

Seth Bullock, the sheriff of Deadwood, built this town immediately after Teddy Roosevelt’s death in 1919.

More than 7,000 gallons of water pour over these cascading red quartzite waterfalls every second.

One of the first intercontinental ballistic missile sites in the United States.

The cliff and rock formations are made out of Sioux Quartzite.

An entire city block built completely out of petrified wood.

One of America's first dinosaur parks gives a window into Depression-era paleontology.

A cemetery housing wild west legends in South Dakota.

This replica stave church looks like a piece of Norway was simply plopped down in South Dakota.

This prehistoric sinkhole lured exclusively male mammoths to their death, much to the delight of science.

The granddaddy of all tourist traps, built on ice water, jackalopes, and a giant dinosaur.

After retiring, Gary Pendergrass turned his yard into a wonderland of outsider art.

Self-built house and sculpture park where the creator can still be seen in a glass coffin.

The quirky collection includes treasures like Elvis' underwear, Bob Barker's toothbrush, and hundreds of sock monkeys.