The footprint of a frustrated devil in Munich's Cathedral.

The prototype for all Nazi concentration camps.

These bronze pamphlets remember a remarkable group of Germans who fearlessly opposed the Nazis in the very center of their power.

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

San Francisco's newly reopened hands-on science museum.

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

A collection of 20th-century automata, penny arcade games, and musical contraptions.

Floating man-made island and upscale restaurant.

An extraordinarily ornate museum in San Diego holds wondrous anthropological treasures.

The remains of a ruined mansion memorialize the 1906 earthquake.

An overlooked and unassuming engineering marvel.

Join the circus for a few lessons to learn clowning, acrobatics, and Chinese contortion.

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

The oldest lawn bowling club in the United States.

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

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

San Francisco's first World's Fair, dedicated to the wonders of California.

Relics of the 1894 Midwinter Exposition continue to delight visitors today.

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

A nondescript building that's been functioning as a speakeasy for nearly a century and a half.

Alleyway plaque commemorating the death of a fictional character in The Maltese Falcon, not far from the author's home.

Only hotel where you can legally launder money.

Furniture tries to escape an abandoned building in San Francisco.

A library built during San Francisco's pioneer times is a student's retreat, bibliophile's sanctuary, and chess player's delight.