Guns that have been defending San Francisco since 1904.

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.

Forgotten and then destroyed by fire, this was once one of the largest saltwater swimming pools in the world.

The grand, column-fronted, sculpture-adorned home of the ambitious digital library.

Over 315,000 preserved amphibians and reptiles in jars.

Russian history in San Francisco.

A man-made island in scenic San Francisco Bay.

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.

Golden Gate Park's historic collection of plants.

A monument to the love people have for their pets.

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

Inside an old airplane hangar, friends and strangers alike play on a massive trampoline.

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.

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

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

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.

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

The remains of a ruined mansion memorialize the 1906 earthquake.

Why walk on this historical site when you can zoom down instead?