If drivers cross the rumble strip on this stretch of Route 66 at just the right speed it plays "America the Beautiful."

The second-largest cave chamber in the world was discovered in 1898 by a 16-year-old and a friend known as "Pothead."

Explore the largest pure gypsum deposit in the world, and go dune sledding while you're at it.

An immersive environment that is part haunted house, part choose-your-own-adventure, and part jungle gym.

These subterranean models show Mexico City's central square during three different eras.

This small piece of railroad history sits behind the parking lot of a chain grocery store.

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

A futuristic hovertrain is parked unceremoniously alongside a nondescript road.

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

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

A small store filled with animal skulls and other curiosities.

A downtown park built on top of unclaimed graves.

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

Neal Cassady may still have an open tab at one of Denver’s oldest watering holes.

One of the greatest heroes of the Titanic tragedy came from humble beginnings to this beautiful home.

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

A Rocky Mountain city provides a happy ending for a pinto pony and his Brobdingnagian red chair.

The huge collection of paintings of the American West is one of Denver's best-kept secrets.

This sidewalk tribute honors Colorado's great culinary creation.

This was once the home of Gahan's Saloon, Denver's most storied speakeasy.

In a small Japanese garden off a busy Denver street, a memorial to a brave, principled politician.

A focal point of in Denver’s skyline for over a century, inspired by a Venetian basilica.

In this case, 'zero' marks the spot where the iconic Old Spanish Trail ends.

The walls of America's oldest masonry fort famously "swallowed" cannonballs.