South Norwood Country Park: Fly On By
Less urban in large
Im and I went to South Norwood Country Park first thing... It was very quiet there, and we saw and heard a surprising range of birds (inc. thrushes, a kestrel, a stock dove, and a collared dove). We also saw several healthy-looking rats scurrying along the banks of a stream which was sweet.
Others here (or right from Demonstrative swan)