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

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

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

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

A huge musical instrument played by the ocean.

America's most famous piece of self-built architecture.

Self-built house and sculpture park where the creator can still be seen in a glass coffin.

A mysterious castle built as a monument to lost love.