[AstralTraveller (David)]

A fair question but not one with a simple answer. Even finding camping within coo-ee of Sydney isn't simple, yet alone where you will be able to observe. You need somewhere where you will be fairly alone so the other campers won't both you, an area with a clearing for the scope but shade for the tent in the morning, dark skies and nearer Sydney than alpha Centaurii. Don't want much do you?

So, what is your shortest distance out of Sydney? I'm guessing west or sw. Of the two perhaps west is better. You get some altitude in the Blue Mtns which is good for observing and there is a lot of National Park. Years ago I 'camped' near Mt Bell, if you can call it that. We got to bed about sunrise and were up about two hours later when the sun got too hot. On the other hand travelling sw is likely to be quicker so you get further from Sydney in a given time. However offhand I can't think of a camping spot before Balangalow (spelling?) State Forest (of Ivan fame).

I wish you well and would be interested in anywhere nice you find, but if you have any sense you'll keep it to yourself.