
I put a quarter on top, to give you an idea of its size.

You can see that some other photographer before me had put a smaller coin on it. I'm not sure if it was a nickel, penny, or dime. The puffball might have grown since its last photo shoot.
It looks like a crater on the moon.

I found it on a trail that had always been closed. It turned out that the sign had been relocated.

(Fel-pro RRR Park, Cary, Illinois, 09/27/2009)