"Well, this is where I live...no. not at the park!"
...so I hope to give some good tips!
For me, tho I live here (and don't know why people would visit, but we all probably think that about our hometowns), Victoria Park is a great draw for nature lovers. People also seem to like the tree sculptures, and I don't think I've ever seen all of them! You can pick up a guide at the tourist bureau - there are some truly awesome carvings!
The picture is of the falls at Victoria Park. They are truly lovely in the winter (the ice is gorgeous) and spring when the water really gets flowing. There is another set of falls (Waddell) up above these.
A great time to visit is in Autumn...the colours are turning and the air is crisp, and it's gorgeous!