Once the largest windmill outside of Holland, with enormous 114 foot sails.

This turn of the century masterpiece has a mysterious goaty interloper.

The remains of a 12th-century chapter house in Golden Gate Park.

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

Radioactivity still cause for concern at this urban explorer's paradise.

A 140-year-old castle with underground caves hidden in San Francisco.

A still functioning vaudeville carousel that has operated for over a century boasts a colorful menagerie and past.

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

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

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

Furniture tries to escape an abandoned building in San Francisco.

The restored and active Victorian-era final resting place of San Francisco.

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

A huge musical instrument played by the ocean.

A shop full of natural curiosities, carnivorous plants, and costumed taxidermied mice.

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

These subterranean storage areas hold emergency water reserves.

An essential stop before plundering, BYO Cutlass.

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

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

This controversial depiction of the "Founder of California" looks as though it was sculpted from mashed potatoes.

A burnt orange monolithic dome structure perched on a hillside near Interstate 280.

A Roman-inspired temple once controlled half of San Francisco's waters.

A classically inspired temple in Redwood City.