A building so large that it has its own weather.

This abandoned NASA launch site is now a memorial to a trio of astronauts who were killed there.

The most decorated dog of World War I is preserved in the Smithsonian.

The 28,000-year-old specimen is remarkably intact.

The remains of Martha, the last known passenger pigeon, serve as a tool to educate about conservation.

Look closely and you’ll notice that the color changes a third of the way up the tower.

A town honors its legacy of traditional American Indian pipe carving with one gigantic pipe.

A beach made of semi-precious green sand on the Big Island of Hawai'i.

The southernmost point in the United States is a beautiful place to look at but a deadly place to wade in.

The deepest lake in the United States, and once the site of epic destruction that lives on in legends.

A throwback train ride transports passengers through one of the lesser-known national parks in the country.

Generations of rockhounds got their start at this beloved, historic mine.

Standing in a state of "arrested decay," this ghost town allows for a detailed peek into Gold Rush life in an unusually harsh climate.

Aqueducts have dramatically changed this old lake, now home to tufa towers and its very own species of tiny brine shrimp.

A house carved into a rock in the 1940s.

This Moab institution functions as both a rock store and a small natural history museum.

Colorful outcrops and cliffs just north of Reno provide a scenic backdrop for hiking and mountain biking.

A man-made island in scenic San Francisco Bay.

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

The statue of John Harvard isn't actually John Harvard—or even, technically, the founder of the school.

A cavernous three-story, 43,800-square-foot basement that was forgotten about for 60 years.

The ancient past meets the retro-future at these dinosaur tracks that are protected by a geodesic dome.

Mine your own precious stones.

Knoxville’s architectural icon was the symbol of the 1982 World’s Fair, even catching the googly eye of Bart Simpson.