This huge dam across the Colorado River caused an armed standoff between two U.S. states.

North America's largest accredited model railroad museum.

The world's largest outdoor organ is played weekly by one of just two civic organists in the U.S.

This historic tower in the California desert promises visitors a "vortex of good vibes".

A UFO scrapyard in the California desert.

Two mammoth statues inspired by equally tall tales lure tourists to this roadside attraction.

Trails through lava-carved tube-caves display sparkling bacteria and a rich history.

One of the most scenic stretches of road in America winds between some of the country's oldest trees.

This ultra-modern California span is actually a titanic solar clock in disguise built by famed architect Santiago Calatrava.

The California capital city once stood 10 feet lower than it does today.

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

Rising out of miles of farmland, these buttes are sometimes called the world's smallest mountain range.

The long, arduous journey of the stones of the Abbey of New Clairvaux.

The seawater playground of gilded-era San Francisco burned to the ground in 1966.

Neoclassical Revival mansion and set of horror cult classic Phantasm.

The original place where water met land in the City by the Bay is outlined in brass.

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

Concrete strongholds stand guard over the Golden Gate.

Not merely a museum – but a whirring powerhouse that offers a subterranean peek into the heart and soul of cable car operations.

A decommissioned Naval base now rents itself out for people who want to blow stuff up.

In all of the 29 years it was in operation, no prisoners ever escaped successfully... or so they claim.

The rusting remains of the largest assembled WWII fleet on the West Coast.

340 bicycles, 65 feet high.

The unedited photograph called "Bliss" has graced the screens of over a billion computers.