Well, I was thinking out by Waveland golf (south of irving park and the lake), which may be busy, or out by the museum campus perhaps.

Hyde Park might make a good spot, somewhere on the UofC campus by the Midway.

Jackson park, also on the water, might be nice.

And vinuneuro, I'm not trying to be difficult, but trekking out to the burbs on a weekend in the summer is sort of counter to the conventional wisdom of the chicagoland community.