One of the many awesome things we did in Sydney included swimming at Bronte Beach. We picked Bronte out of the many, many sea side beaches Sydney has to offer because Lonely Planet guide book stated it was the best for families - not too crowded, shallow rock pool, not too deep swimming area, shady pines to spread a blanket and a playground (essential when traveling with 3 & 5 year olds). The boys had a blast jumping/ slpashing/ being pushed around in the cool ocean water. Hey, we're Canadian, it's warm once you get in!
Attached is a video of our Bronte beach excursion as well as some pics.
And of course we have to attach some iconic Sydney sights - Harbour Bridge and the Opera House, both are truly impressive.