San Francisco’s century-old Christmas Tree.

San Francisco's first World's Fair, dedicated to the wonders of California.

Over 315,000 preserved amphibians and reptiles in jars.

A hidden subterranean installation offers a view of the sky.

Relics of the 1894 Midwinter Exposition continue to delight visitors today.

Big gun installations, built over a massive cemetery, now abandoned & hidden in trees.

The one-time watch house for incoming ships at the Golden Gate now stands abandoned and hidden in trees.

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

Home to one of the world’s largest collections of model yachts.

Perfect your fly fishing technique on their practice ponds.

San Francisco's urban bison herd has persisted in the face of extinction, development, and disease.

Depicting scenes of everyday life - and specific individuals - in Great Depression era San Francisco.

A volcanic tunnel illuminated by natural skylights offers a shaded respite from the desert sun.

The abandoned train depot now doubles as a well-placed rest stop for those who take the road less traveled.

The largest dune field in the Mojave offers a chance of hearing the 'singing sands.'

A pair of large white marble lions guard this stretch of the Mojave Desert, and it is utterly mysterious how they got there.

The ghost town that ended up on Ebay.

A music-filled, booze-soaked oasis in the desert.

Located on 420 acres in the high desert, this spiritual center is dedicated to the "science of the future."

This outdoor observatory offers stellar views and a scale model of our solar system.

The decaying adobe remains of an old homestead are just off the beaten path in Joshua Tree National Park.

One of nature's most well-scheduled phenomenons resides in Wyoming's Yellowstone National Park.

The largest hot spring in the United States is, as the name suggests, a stunning show of natural color.

A beautiful geyser under environmental threat.