If you take swim beaches out of the formula, here's some thoughts on best locations for gold rings:
a) if you MUST hunt turf to angle for gold jewelry, then choose turf that has LITTLE eating/drinking going on. In other words you want to stay AWAY from picnic tables, (where people sit to eat and drink) , BBQ pits (where people have foil wrapped food they bring to cook, and then throw their cans onto the fire which become can nuggets), bleacher stadium seating (where people drink sodas). Because ANYTIME you have eating/drinking going, on, then go figure: foil, tabs, & aluminum. Doh !
b) Hence that leaves sports related venues, where you don't normally have much eating/drinking/picnicking. As was pointed out: basket ball court perimeters, because the players might take off their stuff for safe-keeping and place with their coat and school books at the side-lines. Or football or soccer fields. (where, go figure, frolicking motions are the order of the day). Or sand volley-ball courts. Or mud-wrestle pits.
There's some do's and don'ts for the type land sites which will have better jewelry ratios.