America's most famous piece of self-built architecture.

A "haunted" landmark on the coast of Southern California.

World's largest collection devoted to one fruit.

A world-class observatory in the California desert.

This rugged area of red rocks and arches is often considered one of the most beautiful places on Earth.

It's big, it's a ball, and it's made of twine—the world's largest of its kind.

A collection of 100 brains preserved in jars on the UT campus.

An emerald-green grotto just a short trip from Austin.

Home to Hollywood history and a very special salt crystal.

A sculpture made of 10 Cadillacs as a monument to the "Golden Age" of the American automobile.

A Texas-sized particle collider that was abandoned due to its Texas-sized budget.

Where hills of dirt conceal the burial ground of one of the most powerful ancient Native American societies.

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

Most-visited and most-photographed slot canyon in the American Southwest.

Eons ago, a rushing lava river formed this pristine passage through solid rock.

An arsenic-filled pool in the Grand Canyon takes on the appearance of a giant, overflowing pumpkin.

Rippling sand dunes frozen in the Arizona rock.

An homage to everyone's favorite prehistoric cartoon family.

America's only nuclear missile silo open to the public.

The biggest solar telescope in the world helps reveal the secrets of our sun.

A reproduction of earth's many biomes.

Less a museum than a bizarre fantasy world created by artists and engineers.

A medical facility that has been kept frozen in time.

Once one of the world's great cities, Cahokia was a place of religious worship, trade and mass human sacrifice before being mysteriously abandoned.