I went to Giannini JHS in the early 1960’s and vividly remember what we used to call The Run. Before SI was built, it was out the gym, up Ortega Street to 37th Avenue, then over to the edge of the school, down hill through the sand dunes to 41st Avenue by West Sunset Playground then back across to Ortega and up the hill to the gym. Not sure how long this was but for a young teenager slightly overweight it was a challenge, but everyone in my class eventually made it. I seem to remember we did this pretty often but it was a long time ago.
Speaking of empty lots I was just visiting my old neighborhood in the Outer Sunset and saw a lot on Moraga Street by the Great Highway. I thought that this one might be the only one left today. But in the 1950’s they doted the area and were definite playgrounds for me and my friends.