Thirlmere Lakes is a national park in New South Wales (Australia), 70 km southwest of Sydney, and lying just to the west of Thirlmere, New South Wales. It is part of the Greater Blue Mountains Area World Heritage Site. Covering an area of 629 hectares, it was gazetted in 1972 as Thirlmere Lakes State Park, before being subsequently reclassified as a National Park.[2]