Penn Valley is an unincorporated community located within Lower Merion Township, Pennsylvania, United States. Penn Valley residents share a zip code with Merion, Narberth, or Wynnewood because the community does not have its own post office. However, Penn Valley is a distinct community whose civic association demarcates its boundaries with iconic signs f…Penn Valley is an unincorporated community located within Lower Merion Township, Pennsylvania, United States. Penn Valley residents share a zip code with Merion, Narberth, or Wynnewood because the community does not have its own post office. However, Penn Valley is a distinct community whose civic association demarcates its boundaries with iconic signs featuring William Penn and a farmhouse in blue or red on white, dating from 1930.