what is this huge piece of concrete in my back yard?
Just moved into a home built in '77 and there is a round concrete platform in the middle of the back yard. I'm located in southern arizona in a country club estates. I don't know what it is for. I have had several guesses and one hope... It is 10ft diameter and has 6 bolts sticking up around the circumference. It also has a small PVC pipe sticking up near the edge. I can push a rod down about 12" into the pipe, then it seems to run into a clog or something. I will try to post pictures. Until then, all input welcome.
3)water collection cistern