We come to this park regularly to run around, play tennis, use the playground, swim, and, of course, play baseball. You are looking for a black film canister. It would be best to park in the park's lot and not on the street. Depending on the time of day and time of year, this place could be extremely crowded or completely silent. Bring your own pen.
**1/4/2016: There is now a surprise bonus when you find this cache.**