Although we haven't done this since the early '90s, I am told it was just a great time!
The CFRA's Christmas in July event is like a miniature Field Day, held at Fort Christmas Park in East Orange County. Everyone is invited to bring themselves to participate, bring some food to eat, and to just have a good time. Of course, you are not required to bring food (there will be plenty of that) or anyhing else for that matter.