Hi Kee-Yang,
If its new moon that weekend and your in Sydney some of the folks goto the Pony Club at Mangrove Mountain. Its about 100km north of Sydney and about 1.5hrs drive from the CBD. I usually stay for 3-5hrs depending on the conditions.
Its not the darkest of skies, but its not too bad given its distance from Sydney itself.
I'm happy to give you lift there and back if your staying in Sydney somewhere and if its on that weekend.
Keep an eye on the forum for Pony Club.
Cheers,
Norm