A "gravitational anomaly" located in the redwood forests just outside of Santa Cruz, California.

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

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

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

An artsy hidden staircase leads to breathtaking views of San Francisco.

Golden Gate Park's historic collection of plants.

Olfactory delights in San Francisco's Botanical Gardens.

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

An elaborate gift from Claus Spreckels is now a piece of San Francisco history.

A hidden subterranean installation offers a view of the sky.

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

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

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.

A hidden world of exotic succulents and cacti.

A statue commemorate Tommie Smith and John Carlos's brave protest at the 1968 Olympics, a watershed moment for civil rights.

A giant chess set, minus the psychedelic drug trip.

A pair of pure white felines guard the entrance to a spot of California real estate established as an artist's haven.

Every May, townspeople welcome summer with a bizarre pagan parade led by a man wrapped in garlands.

During the heyday of fishing in Hastings, there were more than 100 of these storage facilities.

An enigmatic monument to the Irish revolutionary who plotted an uprising against British rule.

Local legend says Isaac Newton built this footbridge without any screws, bolts, or nails.

Giant, friendly pelicans in Central London, the most unlikely of places.

A statue marks the exact spot where The Boy Who Never Grows Up made his first literary appearance.