An acoustic anomaly with a mysterious cause sits in the heart of Tulsa.

A Route 66 filling station that was designed to resemble the Hagia Sophia, and is now the symbol of an arts district.

Home to an endangered salamander, a full moon celebration, and a large spring-fed outdoor swimming pool.

Home to the largest urban bat colony in North America, estimated at 1.5 million bats.

Locals dubbed it the "Owl Building" because of its bird-like appearance.

A high-octane shrine to the greatest Texans who ever lived.

This once-booming Gold Rush town is now home to a herd of feral donkeys.

These markers are used to document elevation changes around the famed dam.

Experience a charming 1930s version of "infotainment."

An overlooked monument to the celebrity gangster who helped put the sin in Sin City.

A tiny slice shop hides down an unmarked hallway in a Las Vegas casino.

The first permanent memorial to a unique secret weapon of World War II.

A small metropolis of Pueblo cave dwellings have been carved right into the hillside of this national monument.

This innocuous New Mexico storefront was once the secret jump-off spot for Manhattan Project scientists.

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

A museum devoted entirely to the rattlesnakes and snake-related art.

The fictional star of "Breaking Bad" is memorialized with a real-life gravestone in his hometown.

When life gave this firefighter a forest fire, he made a rough-hewn sculpture park using a chainsaw.

Thousands of pieces of art have been carved into the rock at the site of an ancient volcanic eruption.

A 400-foot-tall tall map of Chicago makes this once-ignored building stand out.

Chicago's Navy Pier on Lake Michigan was a training hub for aircraft carrier pilots during WWII.

The twin towers in this Chicago fountain use 50 foot tall video screens to spit on people.

This southwest-styled home in Santa Fe claims to be the oldest house in America thanks to an ancient bit of foundation.

Wedding chapel's mysterious spiral staircase said to be miraculously constructed.