 It remained open for over 18 years and was the premier theme park in New South Wales for much of its life until its closure in 2004.Wonderland Sydney, then known as Australia's Wonderland opened amid much media attention and publicity on 7 December 1985 with financial backing from the New South Wales State Superannuation Board, James Hardie Industries, Leighton Holdings and Taft Broadcasting (through Kings Entertainment Company) at Eastern Creek on the junction of Wallgrove Road and the M4 Motorway.The developers sought to provide an alternative to the troubled Luna Park Sydney, which had opened and closed multiple times in its recent history.