View from Echo Point in S direction to the Three Sisters Meehni, Wimlah, and Gunnedoo (left side), and to Mt. Solitary (950 m) in the centre of the image. The Blue Mountains represent a section of the Great Dividing Range. Essentially, they consist in a large sandstone plateau with steep or even vertical escarpments leading down to deeply incised valleys and gorges. The Blue Mountains were declared a UNESCO World Heritage Site in 2000.