"We Seceded Where Others Failed."

A building so large that it has its own weather.

A monument celebrating the idea of reaching inaccessible places.

A shape-shifting buy-sell-trade bookstore, born to Beatnik Era spirit.

Quite simply the largest tree in the world (by volume).

The drama of nature in full effect in this Nevada State Park.

Ninety feet off the valley floor is an ancient dwelling put under protection of the U.S. government by Teddy Roosevelt.

See massive fossils that are over 200 million years old in northeastern Arizona.

A reproduction of earth's many biomes.

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

The hike through a narrow river flanked by the 2,000-foot-tall walls of Zion Canyon is one of the best in the world.

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

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

The ancient dwellings of the Puebloans, located in the cliffs of majestic mesas.

On the Fourth of July this area will transform into a Pompeii-like storm of falling embers and ash.

One critic described it as "middle Mussolini, early Ramses, and late Neiman-Marcus." Another called it an architectural "natural disaster."

There’s a hidden military meme engraved on the World War II Memorial.

Members of Congress have traveled between the buildings on Capitol Hill for a century hidden from tourists, press, and storm clouds.

The walls of the iconic dome are hollow and have a secret stairway.

Home to items never before seen by the public.

These chunky stone towers out in Lake Michigan are the key to Chicago’s drinking water.

These mansions date back to Chicago's days as a brewer's paradise.

A hot dog stand where the heads are just as hot as the dogs.

The palatial McDonald's that inspired Wesley Willis.