When ecosystems collide in the arid Southwest.

Located in the world's highest-altitude Dark Sky Community, this observatory welcomes amateur and professional astronomers alike.

See six states, pickled freaks, rocks, and antiques.

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

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

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

A futuristic hovertrain is parked unceremoniously alongside a nondescript road.

A hotel with a rich Wild West history of miners and bootleggers.

Legends surround this jagged rock formation in the New Mexico desert.

The marker offers a rare chance to be in four U.S. states at once, though there's some controversy over its geographic accuracy.

This memorial pays homage to Pueblo's four Medal of Honor recipients.

The narrow mountain road that carves a path between Florence and Victor is tied to ghost towns and ghost stories.

This razorback ridgeline has doubled as a scenic drive since the early 1900s.

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

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

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

This historic stone barn is the former home of legendary cattleman Charles “Lonesome Dove” Goodnight.

Roaming bison and a spectacular view at the highest point in Nebraska.

A monument to the forgotten French explorers and their landmark expedition.

The lowest point in South Dakota and the source of the Minnesota River.

Thousands of majestic trumpeter swans fill this park, sounding distinctly like a certain brass instrument.

20,000 pieces in a Frank Gehry-designed building.

Opened in 1956, the first modern indoor shopping mall in the world was inspired by the shopping arcades found in European cities.

The basement bowling alley of this St. Paul dive bar is decorated with thousands of dollar bills.