Hornsby is a suburb of Sydney. It's on the upper north shore, on the train line and has a Westfield (AKA mall). It's a reasonably sized train station, and various train transfers happen there. Outside of the Westfield it's rather dingy and not terribly exciting. And, really, if the Westfield is its most exciting attribute (oh wait! There's an Oliver Brown!), well, I think that speaks for itself. I've been going there a bit lately because one of my best friends recently moved to the Central Coast, and it's roughly halfway for us to meet up and hang out. And get all our shopping done. And chocolate eating. And once, not unlike our trip to Minto, we happened to catch a fringe element of one of Sydney's major festivals (this time, a talk of the Writers' Festival -- which was notably better than our Minto expedition, though also slightly less story-worthy. Though I will mention that they served little sandwiches cut into triangles. And fruit. And cake. For free! Can't imagine that in Minto.) there.
And now you know everything there is to know about Hornsby.