A monumental cross hides in the trees in Golden Gate Park.

This tall and trim architectural oddity is one of the skinniest buildings in San Francisco.

Only hotel where you can legally launder money.

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

This grinning pup statue is all that's left of what was once a ubiquitous Bay Area diner chain.

One of few lasting examples of the brief octagon craze that developed into folly.

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

The key to turning shifting dunes into the green oasis of Golden Gate Park.

Recovered from the brink of extinction, at home in the Financial District.

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

A pair of mutilated bronze octopuses slump at the base of the monument honoring California's admission to the U.S.

A brooding mansion of clinker brick stands out among the Victorian houses of Pacific Heights.

A garden oasis filled with flowers mentioned in the works of William Shakespeare.

A speck of nature and art in one of San Francisco’s most notorious neighborhoods.

San Francisco's oldest operating hotel, with a Victorian atmosphere and a "haunted" fourth floor.

The miraculous hydrant that saved the Mission District in 1906.

A man-made island in scenic San Francisco Bay.

Longtime headquarters of controversial boys' club for the world's wealthiest and most powerful.

Half of a house.

A monument to the love people have for their pets.

This partially buried wreck is one of the most complete of its kind but is only revealed when the sea allows.

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

An overlooked and unassuming engineering marvel.

The stones that traveled from Spain to eventually become a holy place for San Francisco's nature worshippers.