A quick Google throws up the Otmoor RSPB reserve and the Sydling Copse nature reserve. I actually kind of like the idea of adding the Berks, Bucks and Oxon wildlife trust to my list of charitable contributions - it's rather my sort of thing, after all.
So anyway. My question is (a) has anyone been to either of these? or (b) does anyone know of any other nice local tramping around locations well away from the traffic and preferably with woodlandy bits?