California's first suspension bridge.

Hidden inside a gift shop that doubles as a museum, this gargantuan yo-yo can only be operated by crane.

A picturesque example of brute-force engineering conquering nature.

A rugged lava field dotted with molds of the ancient pines that were growing when the volcano erupted.

The world's last remaining store of its kind.

Boats and fish both find their way through this massive hydroelectric structure.

This rare, carefully curated collection showcases the history of neon inside a grandiose Elks lodge.

The original span of a high bridge across the deep Crooked River Gorge has been preserved for pedestrian use.

A house built from trash known as the poor man's Hearst Castle.

This sci-fi gazebo located in a Washington power town is made from old bits of industrial electrical equipment.

This bridge provides safe passage for squirrels.

Where a staggering 747 ships were constructed during World War II.

The perfect spot for a picnic, right next to a giant ballistic missile.

The oldest Naval chapel in the United States is home to an incredible collection of Tiffany stained-glass windows.

A sparse, solitary sequoia still stands as a living tribute to the famous conservationist who planted it—but it's dying.

The oldest Naval cemetery on the West Coast.

The former Naval shipyard is open for exploring - mostly.

Before he was America’s most famous preservationist, John Muir was an ingenious mechanical inventor.

This California museum is home to one of the largest collections related to the 'Treasure Island' author.

A porcelain company's former dumping ground, completely covered in pieces of collectible ceramics.

A huge collection of rocks, gems, and crystals.

The haunting ruins of Jack London's dream house.

Where a railroad loops under or over itself to rise or drop more than 70 feet in a short distance.

This enormous fiberglass cow near Death Valley National Park once graced a casino roof in Las Vegas.