Home Postcodes by state SA 5076 Postcode 5076 5076 is the postcode for 2 localities in SA: Athelstone and Castambul. Localities with postcode 5076AthelstoneSACastambulSA Postcode 5076 State or territory South Australia (SA) Localities 2 Council area Campbelltown; Adelaide Hills Council area based on Australian Bureau of Statistics data (ASGS Edition 3), CC BY 4.0. Postcode 5075 · Postcode 5081