I recently visited The Raptor Foundation in Cambridgeshire. They're a charity who provide medical care for injured raptors, return rehabilitated birds to the wild, and provide sanctuary for unreleasable raptors. It's a great place to visit to get up-close to some fantastic birds-of-prey, and it provided me with a great opportunity for photography.
While this is not true wildlife photography, it's great practice for me, to improve my skills in getting the focus & exposure right, and learning to track birds-in-flight in the viewfinder. This is a very difficult skill, and one which can only be mastered in time. I can also achieve the kind of close-ups that would simply be impossible in the wild for most species.
The Raptor foundation keep over 250 individual birds, including owls, hawks, falcons, buzzards, and eagles. A day visit affords you the time to see most of the birds in their aviaries, or out on perches. Then three times daily (or twice in winter), they're flown in a display lasting well over an hour each, and comprising several different types of bird. It's a thrill to witness, and joy to photograph.
For photographers, they run special "photographic days", which I haven't tried yet, but have booked for next month. So I'll see how that compares to a normal day visit.
In summary then, I can't recommend The Raptor Foundation highly enough. The entry price is modest, and the money goes entirely towards the charity, and running the foundation.