I recently went there and looked up the Sutro Baths, which opened in 1896 by Adolph Sutro (a philanthropist and one-time mayor of San Francisco). The baths were a place of great joy and communal fun out by ocean beach in an area that was, at that time, fairly desolate.
The baths consisted of seven pools of varying degrees (six of which were salt water pulled from the Pacific Ocean through great feats of engineering). There were rings, trampolines, rafts, and slides, and the baths could fit 10,000 people. No matter your social status, everyone who entered the baths wore a rented woolen bathing suit and it cost just $.25 to swim. I believe it included at least two restaurants where people could sit in the terrace area and watch the swimmers for just $.10.
There was a museum at the entrance of the baths full of exotic stuffed animals and strange plants. Sutro wanted the baths to be for all people so he even built his own railway out to the baths ensuring people would be able to get there for a cheap price (he charged $.05).
The baths went through many incarnations but finally burned down mysteriously in 1966. Today you can visit the ghostly ruins.
Here are a few of the original entrance tickets from the baths:
And a few of the programs highlighting various happenings at the baths:
Including the original program from the opening of the baths in 1894:
The History Center is a great resource and full of inspiration. I plan to use it a lot during my thesis year.