Just wanted to recommend a trip to Old Down Country Park near Thornbury.
I went there today as it has just reopened after being closed for 4 years. It is much improved and the staff/owners are still working on it. There are the usual farm animals as well as wallabies and llamas and possibly other animals which we did not see.
There is a play area with sandpit, toys and trampolines and another which is more of an assault course for older kids. I did spy another play area when we left but we didn't use it. The food was nice too!
It was really nicely laid out and only £5 for an adult and £2.50 for children pver 2 and open from 8 til 8.