Person of Interest
Baseball Diamond
Fermin Ordoñez is reunited with his family at the park in episode 2x09 “C.O.D.”.
Source: Person of Interest — Wikia
Playground
Shaw mourns Root at the park where Reese joins her and they get a new Number in episode 5x11 “Synecdoche”.
Potter's Field
Reese and Finch watch Root being buried in an anonymous grave in episode 5x11 “Synecdoche”.