A 39-acre park spanning the borders of Placentia, Fullerton, and Brea — hence the name — built around a small lake that you can walk all the way around in under half an hour. There are picnic shelters, playgrounds, a fishing pier, and enough waterfowl to keep small kids entertained for an afternoon.
It is the closest large green space to central Placentia and locals treat it as a default outdoor venue. Early morning and evening are the most pleasant; midday in summer is brutal in the unshaded stretches.