I’ve been going to China Beach since the 1950’s and although I don’t live in the city, it’s still my go to beach in SF. In the 50’s the building was pretty active. On each end were the changing rooms for men and women. These included hot showers! I think the heat went away by the 70’s. Next to the men’s was a concession stand which closed in the sixties. On top of the structure was a sun deck and the lifeguard space. In back were two restrooms. Today the building is completely shut down and except for the sun deck, serves no purpose.