Southbank is a suburb in its on right, with its own postcode, 3006. It begins as you cross the southern bank of the Yarra River and covers quite a large area west of St Kilda Road and as far south as Dorcas Street. At a guess I would say it has the highest number of residential and office towers of anywhere in Melbourne, perhaps Australia. There are some pleasant areas within Southbank, but much of it is canyons of tall buildings, although it has a better feel to it than Docklands.
There is little reason to hang around the back streets of Southbank. Most of its history has been destroyed and much of it was only industrial of no great merit anyway. I was catching the number 1 tram after coffee at Southgate. If you are a little confused, Southgate is an area within Southbank.