I've seen people set up a tent down by the bathroom, in the grass just past the gravel parking area. Seems a bit uneven for me.
If you go on line I bet you can find the rules for camping in the area. I once came on some amish kids camping out by one of the ponds. I don't think they were suppose to be there.
There is one good campsite that has a area cleared that would be good for a tent.