Golden Gate Park's historic collection of plants.

This private residence was the template for one of the most beloved television homes of all time.

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

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

The randomness of this wall of lava lamps helps encrypt up to 10 percent of the internet.

An essential stop before plundering, BYO Cutlass.

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

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

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

Staircase winds down the side of Telegraph Hill through gardens, wild parrots flying overhead.

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

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

A walk-in working camera obscura produces 360-degree live images of the San Francisco coast.

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

Carnivorous plants, medieval aphrodisiacs, and the largest original wood structure glass conservatory in the western hemisphere.

A winding path built in secret on the edge of the continent.

A huge musical instrument played by the ocean.

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

The U.S. Navy's last diesel-electric submarine rests half-submerged in the middle of Portland.

Home of Howard Hughes' Spruce Goose.

The wooden airship was the largest flying boat ever built.

A beautiful 62-acre Catholic shrine and botanical garden.

The seamy, underground secrets of Portland's criminal past.

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