A massive volcanic plug is now a protected area that hosts a number of bird species.

A man-made island in scenic San Francisco Bay.

Early prototype for Frank Lloyd Wright's Guggenheim.

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

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

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

Tenacious mummies survived dental problems, eternal entombment, and more than their fair share of devastating fires.

A promotional sun clock on the site of San Francisco's great raceway.

Since 1973, this block has been home to the most concentrated collection of murals in San Francisco.

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

A library and museum dedicated to typography.

This print shop boasts one of the largest pinball arcades in San Francisco.

A Barbary Coast watering hole built into a Gold Rush shipwreck.

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

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

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

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

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

This 19th-century church is now a popular roller rink.

Big gun installations, built over a massive cemetery, now abandoned & hidden in trees.

The remains of a ruined mansion memorialize the 1906 earthquake.

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

A 300-ship graveyard, with a few still visible at low tide.

The tea room that pushed the boundaries of adorable straight into...we can't find the words.