Lilac tree (maybe?)

Update 30 oct 2011: Fionie the Green Thumb and font on all things horticultural has provided the answer - these are Cape Chestnuts: calondendrum capense, natives to Cape Town. The Cape Floral Kingdom is both the smallest and richest floral kingdom on Earth. They usually grow incredibly well in Australia (Gondwanaland and all that....)

Last Sunday, a beautiful day in Sydney, I was swimming at Bexley pool. I looked up and saw these magnificent flowering trees.

Apart from the beauty of the blossoms, they had the most magnificent scent.

I wasn't sure what they were, but googling seemed to suggest they are lilac trees. I'm still not sure though, so if anyone knows, I'd appreciate help!

Further investigation indicated lilacs are cool climate trees, liking frosty conditions.

That doesn't fit too well, cos the suntrap at Bexley pool doesn't speak of frosts.

Purple lilac flowers are supposed to symbolise the emotion of being in love; white lilacs represent youthful innocence.