Mongers Lake, known by its Noongar name Galup (also called Keiermulu), is a large urban wetland situated on the Swan Coastal Plain in the suburban area of Wembley, Western Australia, less than 5 kilometres from the Perth central business district. The lake covers approximately 70 hectares of predominantly open, shallow water and sits within the broader 110-hectare Galup Reserve alongside the Mitchell Freeway. A small island, Monger Island, of about 1.3 hectares occupies the south-west corner of the lake. While the reserve is a popular destination attracting up to 12,000 visitors per week for activities such as birdwatching, walking, and cycling, the fish community in the lake is composed entirely of introduced species.