It's Monkey Forest, at Trentham Gardens. Several acres of woodland have been fenced off, with Barbary Macaques (140 ish - they keep breeding) wandering around. No enclosures inside the compound, so the visitors and macaques mingle. The secondary aim is to return some of the stock back to wild populations, so that numbers at Trentham should remain constant, and ensuring survival in the wild. Last time I went, managed to get a small crowd excited about a nuthatch that was running up and down the tree there.
Also, Trentham is more than just that It's a mature wood with
Fallow Deer, great spotted woodpecker, jays, barn owls. The river and lake are home to kingfisher, herons (one of largest colonies in england) cormorant and supposedly
Otter (which I've yet to see!). The formal Italian Gardens are gold medal winners at Chelsea too.
Think I've covered it all! Admission to Monkey Forest is a fiver, the woods and lakeside walk are free.
Some of my shots from both Monkey Forest and Trentham are here
http://carljervis.fotopic.net/c611285.html