Lake Monger is a large urban wetland on the Swan Coastal Plain in suburban Perth, Western Australia nestled between the suburbs of Leederville, Wembley and Glendalough. Less than five kilometres from the city of Perth and situated alongside the Mitchell Freeway, it runs approximately north-west to south-east towards the Swan River and consists of 70 hectares of mainly open shallow water with an island of 1.3 hectares in the south-west corner.