RSPB Greylake is a reserve with a compact area for visitors but is a huge area of wetland for the birds. At certain times of the year it is a temporary home to many thousands of ducks, lapwing and waders. Quite frequently you can spot Marsh Harrier, Peregrines, Hobbies and Merlin.
Being on the flat wetland it has a variable amount of water. In winter the marsh is usually flooded and covered in ducks. During the summer it is drier and hosts a different set of wildlife.
It has an excellent hide and some additional viewing platforms. The car park has some feeders set up and you can relax and watch a variety of small birds use them up close.
Photos relating to Greylake can be found here.