 Several other conservation reserves and areas of bushland are adjacent or close by the Garigal National Park, including the Ku-ring-gai Chase National Park, the Sydney Harbour National Park, the Manly Warringah War Memorial Park (commonly known as the Manly Dam Reserve) and a number of areas of Crown land and other reserves in Warringah, Ku-ring-gai and Willoughby local government areas.The national park is defined by the following boundaries

A "Dry Sclerophyll Forest", Garigal National Park is home to a wide range of fauna, including birds, snakes and a wide range of native mammals (such as bandicoots, koalas, wallabies).There is also a number of introduced pests, including rabbits and foxes.