This is at Indianapolis for the 500; probably late '20s or early '30s (just a guess; maybe some of you here know for sure). The tradition of building your own "bleachers", even on cars, in the infield went back to the very first 500. The photo was taken on the main straight just south of the Garage Area showing in the background. After WWII the homegrown bleachers showed up all over the infield. Finally, there was a collapse of a very tall scaffold that killed two spectators putting an end to management allowing people to build any raised structures.