A tunnel with windows, so you don't miss out on the impressive views.

Red sandstone structures dominate this landscape, which has been inhabited for some 5,000 years.

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 immigrant bridge once spanned the Thames but is now a fixture of an Arizona city.

This 4,000-foot-diameter hole is touted as "the most well known, best preserved meteorite crater on Earth."

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

Stepping away from the glitz of mobsters and casinos to learn about the other history of Vegas.

10,000 flowered plants bloom in the City of Roses.

This unassuming cheese empire in rural Oregon churns out more than 150,000 pounds of cheese each day.

The largest wooden building in the world now houses a fascinating collection of aircraft.

On the Oregon coast is a natural hole that seems to be draining the sea.

Only known mainland rookery of the threatened Stellar sea lion.

Fifty years after a “blast blasted blubber beyond all believable bounds,” this idyllic natural area commemorates the carnage.

This colonial mansion has been home to a staggering number of American historic figures.

This palatial botanical garden is home to one of the largest pipe organs ever installed in a private residence, and a piece of Wood's cycad.

The oldest surviving botanic garden in the United States.

One artist's love letter to his city and its citizens plays out across dozens of bright murals painted on the sides of decrepit buildings.

An Irish Memorial commemorating those who perished due to potato blight.

This beloved marketplace mascot poops money and grants good luck.

A daily replay of the experiment that proved the rotation of the Earth.

The remnants of two World's Fairs are here, complete with a 12-story globe, a mini-Manhattan, and a UFO-shaped pavilion.

The world's largest public collection of PEZ memorabilia.

Housed in a century-old building, this museum's dedicated not just to soft drinks, but to the free enterprise system.

This small park features a monumental fountain wall, providing a great photo opportunity in the middle of Houston.