Ku-ring-gai Chase National Park is a national park on the northern side of Sydney in New South Wales, Australia. The 14,977-hectare (37,010-acre) park is 25 kilometres (16 mi) north of the Sydney central business district and generally comprises the land east of the M1 Pacific Motorway, south of the Hawkesbury River, west of Pittwater and north of Mona Vale Road. It includes Barrenjoey Headland on the eastern side of Pittwater.

Sydney is the capital city of the state of New South Wales and the most populous city in Australia. Located on Australia's east coast, the metropolis surrounds Sydney Harbour and extends about 80 km from the Pacific Ocean in the east to the Blue Mountains in the west, and about 80 km from the Ku-ring-gai Chase National Park and the Hawkesbury River in the north and north-west, to the Royal National Park and Macarthur in the south and south-west. Greater Sydney consists of 658 suburbs, spread across 33 local government areas. Residents of the city are colloquially known as "Sydneysiders". The estimated population in June 2023 was 5,450,496, which is about 66% of the state's population. The city's nicknames include the "Emerald City" and the "Harbour City".