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

This giant pocket watch is the third iteration of a local landmark that has been standing just off the Santa Fe Plaza for over 100 years.

The oldest continuously occupied public building in the United States.

There are eight natural springs around town, each with a slightly different taste.

While most of the games in this arcade take quarters, that would have been a small fortune when they were made.

Thanks to a quirk of elevation this gift shop produces magic doughnuts that are found nowhere else on Earth.

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

Strange red rock formations that have been attributed to a higher power for hundreds of years.

This super steep hike ascends 2,000 feet in less than a mile.

The largest free-standing aquarium in the world resides in a hotel lobby in Berlin.

A bronze plaque marks the site of the only show the "King of the Soul Singers" ever missed.

Home to a protest movement, a bombing, and a dramatic change in labor history.

This historic hotel invented the chocolate brownie.

A spectacular remnant of an Adler and Sullivan masterpiece that was destroyed in 1972.

Once at the center of U.S. finance, the historic Trading Room was meticulously recreated piece by piece and rebuilt in the Art Institute.

Each of these gorgeous, intricately decorated rooms is painstakingly crafted to the scale of 1 inch: 1 foot.

These pretty kitties killed and ate as many as 135 railway workers.

At Chicago's revered Field Museum, visitors are invited to learn about and literally explore DNA.

Where dioramas can follow you home.

This ornate Victorian marketplace was the setting for Diagon Alley and the Leaky Cauldron in the Harry Potter films.

This coffee shop lies hidden beneath a historic church.

Claiming to be the oldest hat store in the world, this historic haberdashery had a hand (and a head) in the creation of the Bowler.

The John Snow Memorial marks the epicenter of London's 1854 cholera epidemic.

Tourists who rely on a transit map to find the iconic Beatles location often end up in a far-off neighborhood.