High Quality Content by WIKIPEDIA articles! The Sydney Basin is a sedimentary basin on the east coast of New South Wales, Australia consisting of Permian and Triassic sedimentary rocks. It is named for the city of Sydney which is centred within it and stretches from Newcastle in the north to Batemans Bay in the south, and west to the Blue Mountains towards Lithgow, and up until the edges of Mudgee in midwestern New South Wales.