5 /5 Kris: According to the plaque there was an irrigation ditch that ran through here that powered a grain mill. As the plaque explains, a mob of irate citizens became sick of the smell and garbage accumulaying in the ditch and filled it in one day. After that the mill ran on diesel.
Now there is just this cool little park across from the fresno city hall, library, and other local landmarks. It is a great downtown for a walk.