Parish of Petersham  Petersham Parish is one of the 57 parishes of Cumberland County, New South Wales, a cadastral unit for use on land titles. It is located to the south of Iron Cove, Rozelle Bay and the Parramatta River, and to the north of Cooks River. It includes the suburbs of Balmain, Leichhardt, Petersham, Newtown, Marrickville, Tempe, Glebe and St Peters.