Plans for making Wollongong, Sydney and Newcastle a single city has been around since the 1960s, with a report titled "The Committee for Sydney" having a chapter called "The Sandstone Mega-Region, Uniting Newcastle, the Central Coast, Sydney, Wollongong" (since all these cities sit on the geological region called the Sydney Basin, which is made up of Sydney sandstone). The report discovered that the link would benefit the “six cities” within the region, which are: Illawarra and Wollongong, the Western City (Greater Western Sydney), the Central City (Parramatta), the Eastern City (Sydney CBD, eastern suburbs, Northern Sydney), the Central Coast (Gosford) and Newcastle (including Lake Macquarie).