The legendary building that needed ghostly approval before being built.

Breathtakingly blue walls shimmer inside the "Glacier Behind the Town."

This grand mansion has starred in everything from Bones to Buffy.

Neither Spanish settlers nor anyone since has been able to tell who built these strange California rock walls.

This one-block alleyway is stuffed with street art that is colorful, cultural, and intensely political.

A masterpiece in Golden Gate Park by virtue of the artist’s debt.

Faceless white figures loom over the city from the rooftop.

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

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

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

Adolph Sutro's little-known, geographically inaccurate, deprecated monument.

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

Art from the latest counter-culture; kids who dye their hair blue and believe the future will be a post-apocalyptic water world.

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

A monument to the love people have for their pets.

Gold Rush-era tombstones line the park's paths.

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

An overlooked and unassuming engineering marvel.

San Francisco's oldest surviving monument and meeting place for 1906 survivors.

San Franciscans leave gifts and messages for the magical beings that live behind the tiny, mysterious door installed on a tree in Golden Gate Park.

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

The oldest burial ground in the city, final resting place of city founders, Ohlone natives and murderers alike.

Visible below the waves are memorials to the city's Gold Rush dead.

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