I can thoroughly recommend Honey Brook Farm in Wimborne (out on the Cranborne road). There are beautiful country walks, a chance to see lots of animals, a big play area and lots of additional activities - check out their website www.honeybrook.org. There is also a great butchers, bakers and cafe/farm shop on site. There is no parking charges but they do appreciate a donation of £2.50 per person. There is plenty to do for the whole family and you can easily spend the whole day there. Enjoy!