The Library of Congress has a fun YouTube account that has samples of some of the rare videos they possess. I found a 1902 clip by Thomas Edison that shows bathers frolicking at the Sutro Baths in San Francisco. Adolph Sutro built the public bathhouse in 1896; it burned to the ground during its demolition in 1966. Based on this video, it had a 50-foot-high water slide which was all kinds of fun. In a letter published in a 1998 San Francisco Chronicle, an elderly man named Bill Roddy recalls the Sutro Baths when he was a child in the 1930s, when it had started getting a little run down. An excerpt:

“I went outside and walked a few feet to Sutro Baths, a massive Victorian structure that was beginning to show its age. I think I paid 25 cents admission. I was given a swim suit (we could not bring our own) and a meager towel. The suits were not trunks. They covered all of my puny body with straps that went over my shoulders, and they were made of wool with ‘Sutro Baths” across the front in white letters. As if anybody would have wanted to steal one!

I changed into my woolen suit and raced down the stairs to the baths. There were eight or nine pools with temperatures ranging from hot to ice cold. The biggest pool had a waterwheel.”