RSPB bird sanctuary at Fowlmere near Cambridge is a relatively small but important wetland conservation area. And being a wetland area it attracts a vast array of our avian friend all year round. It is also extremely popular – all year round. The day we went, mid afternoon, mid November, the car park was close to being full. However the car park not being that large, does put a natural constraint on the number of people within the sanctuary at anyone time.
There are a number of walks, the longest of which is easily walkable within a hour and a half, although if your purpose is actual bird watching, well you will take as long as you take.
The low winter sun the day we visited gave some terrific reflections off the marsh reeds. If you are looking for images of birds, you will be disappointed. The birds were there, but the hides, together their access paths were closed. So no birds, but we do have a dragon.