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

These picturesque Hawaiian falls are home to a rare species of fish that uses a special sucker to climb up cliffs.

This Hawaiian cattle ranch acts as a museum devoted to the island cowboys that predate the wild west.

Earth's tallest volcano is sacred to Native Hawaiians, and home to a dozen world-class observatories.

These ancient sacred grounds granted amnesty to those who managed to reach them.

38-story baroque tower reflecting Detroit's rise, fall, and possible rise again.

Glass and concrete building designed by Albert Kahn.

These enduring murals depicting a distinctly Marxist tribute to capitalism could not even be defeated by McCarthyism.

A Beaux-Arts triumph set to become Ford's innovation campus

Detroit’s downtown castle is one of the oldest structures in the city.

Controversial tribute to the heavyweight champion boxer who grew up in Detroit.

A self-built castle made by a mysterious man.

This California tree is the single source of the state's entire orange industry.

The hidden jewel of Disneyland: a members only playground for the Disney elite.

A tiny survivor of the Donner Party disaster.

An eccentric home stands out in an otherwise average neighborhood with mosaics, mini topiaries, and kinetic sculpture.

The capitol city's oldest existing cemetery.

I Street Bridge is the heaviest swinging center bridge in the United States.

Special tunnels built so that frogs won't be killed when crossing the highway.

This graffiti-covered bridge is the quintessential vision of a place for disillusioned youth to escape the complexities of burgeoning adulthood.

If you dial the number in this abandoned office window "Sam Spade’s" secretary will ask you to leave a message.

The last remaining relic of San Francisco's glittering 1915 Panama Pacific Exposition.

San Francisco's newly reopened hands-on science museum.

This concrete tangle of square pipes has stood as a proud thorn in the city's side since the '70s.