The Blue Mountains is a mountain range located north-west of Sydney in New South Wales, Australia. The Blue Mountains region borders on the Sydney's metropolitan area, its foothills starting about 50 km north west of the state capital city of Sydney. The region is bounded by the Nepean and Hawkesbury rivers in the east, the Coxs River and Lake Burragorang to the west and south, and the Wolgan and Colo rivers to the north.
The Blue Mountains covers a range of mountains, plateaux and escarpments extending off the Great Dividing Range. Several towns are situated on its heights, including Katoomba, Blackheath, Mount Victoria, and Springwood. The Blue Mountains area includes the local government areas of the City of Blue Mountains, the City of Hawkesbury, the City of Lithgow and Oberon Shire.