Onion, since I could only choose one I said the event area. But there are several good choices, because it's wherever people have gotten together or played. The more people, the more losses and harder for them to remember where they might have dropped something. Kind of a trick question.
I always pick the woods first. Alot of Hanky-Panky there & alot of chances to loose stuff, Also , I would try the Thick Growth areas, because other detectorists may not have. I also noticed around here, Alot of the Parks, the Wooded Area, Used To be the Park, then either Laziness at keeping things trimmed, or Purchase of additional land caused the main areas to move.
Choose "Picnic Grove" but I'm hoping a Fair Grounds will also be a good as I just got permission to work a county Faigrounds after April 15th of this year.