I've lived in the Chicago area for over six years now and it was only until this summer that my wife finally made me go to the Chicago Botanic Gardens in early July. I loved it. The Gardens are simply stunning, especially considering the extra-dry weather we had. My favourite is the English Walled Garden. I need to visit more places like this. Calming. Beautiful. Natural. Refreshing.
See my Flickr photo stream of the gardens here. We've went twice in July but I reached my Flickr upload limit so had to wait until August to upload a few more. I hope to go a few more times this year (good place to take visitors too).