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

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

One man's love of natural beauty led to the creation of this hidden granite monument.

Dentist's hated concrete colossi are now beloved icons of the community.

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.

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

This rare example of a "tidefall" is a spectacular drop from the cliffs down onto the beach.

California's own medieval Italian castle, authentic down to the 300-year-old iron maiden in the dungeon.

The lowest point in North America is home to an undrinkable pool surrounded by fields of geometric salt flats.

The largest drain hole in the world.

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

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

Aqueducts have dramatically changed this old lake, now home to tufa towers and its very own species of tiny brine shrimp.

A collection of 20th-century automata, penny arcade games, and musical contraptions.

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

Non-profit time travel mart sells goods you would need for a trip through the fourth dimension.

A huge musical instrument played by the ocean.