This history of San Francisco’s Parkside district (aka part of the Sunset) is fascinating. It includes such wonderful tidbits as this:
The unpopulated remoteness of the Sunset District made it an appropriate location for the manufacture of explosives. The California Powder Works, also known as the Hercules Powder Works, ran a plant near Fourth Avenue in the Inner Sunset before accidental explosions in 1870, 1872, and 1877 closed it.
Highly recommend if you are an urban history nerd.