I used to come to this park with my Mum and Grannie when I was a child. It always seemed a little magical as we didn't come here often, but when we did, we had to walk down back streets to a little fence, and lo! into sight came a much cooler playground than I was used to, and ducks in the lake, and then a little pathway at the other end of the path reminiscent of fairy pathways in kid's books. I'm older, but the ducks are still around.
This cache is a black bison tube. BYO pen.
UPDATE: Due to the bridge having been painted, and all the lovely stream vegetation now stomped on, the cache and location have changed slightly. The coords remain the same. It is now a 200ml systema container. The hint has been updated. As usual, there is no need to trample anything living :).