This could also be called Marksam Park Hidey-Hole v 2.0, as I had a cache in this park previously that kept getting disrupted, presumably by kids, potentially by animals. Hopefully this new location is a bit more protected. Many local kids build forts in this forest, and it's popular for dog walkers, so there is potential for muggles depending on the time of day.
I have many childhood memories of this park, both the forested area a the bottom of the hill and the playground at the top (which has changed considerably since I played there). Bring your kids for a search and a play!
Cache will probably be buried when it's really snowy, but should be otherwise available.