The 171 km ² seat stretches from Hallett Cove and O'Halloran Hill in the north to Sellicks Beach in the south , including the suburbs of Aldinga Beach , Christie Downs , Christies Beach , Hackham , Hallett Cove , Huntfield Heights , Lonsdale , Maslin Beach , Moana , Morphett Vale , Old Noarlunga , Onkaparinga Hills , Port Noarlunga , Reynella , Seaford , Sellicks Beach , Sheidow Park , Port Willunga , Trott Park , Woodcroft , and parts of Happy Valley and McLaren Flat .
It includes the suburbs of Aldinga Beach , Christie Downs , Christies Beach , Hackham , Hallett Cove , Huntfield Heights , Lonsdale , Maslin Beach , Moana , Morphett Vale , Old Noarlunga , Onkaparinga Hills , Port Noarlunga , Reynella , Seaford , Sellicks Beach , Sheidow Park , Port Willunga , Trott Park , Woodcroft , and parts of Happy Valley and McLaren Flat .