Home Postcodes by state WA 6056 Postcode 6056 6056 is the postcode for 17 localities in WA: Baskerville, Bellevue, Boya, Greenmount, Helena Valley, Herne Hill and 11 more. Localities with postcode 6056BaskervilleWABellevueWABoyaWAGreenmountWAHelena ValleyWAHerne HillWAJane BrookWAKoongamiaWAMiddle SwanWAMidlandWAMidvaleWAMillendonWARed HillWAStrattonWASwan ViewWAViveashWAWoodbridgeWA Postcode 6056 State or territory Western Australia (WA) Localities 17 Council area Swan; Mainly Swan, partly Mundaring; Mundaring; Mainly Mundaring, partly Swan Council area based on Australian Bureau of Statistics data (ASGS Edition 3), CC BY 4.0. Postcode 6055 · Postcode 6057