It’s interesting to see that around the CBD, a subtle line is often marked on the pavement, where (I’m assuming) the publicly-owned pavement ends and the privately-owned property begins.
Quite a few buildings include this kind of open space, particularly at the front, and I would assume the boundary would have legal significance.
In some cases it’s less subtle, where they’ve made no effort to match the paving styles on the private land to the public footpath.
An infamous boundary among Melbourne’s news media is Southern Cross Station. Security guards will descend if the media set up their cameras on the wrong side of the line without authorisation — even when the story has nothing to do with the station itself. That’s why in news reports you’ll often see them looking into the station, having filmed from the footpath outside. Why go there? Well for some (for instance channels 7 and 9) it’s close to where they have their offices — and unlike other CBD railway stations, you can just about see platforms and trains from the street.