Longham Lakes are two recently constructed reservoirs that serve the Bournemouth/Poole area, they may actually have been gravel pits prior to being made in to reservoirs. There are two large lakes, one managed with wildlife in mind, the other stocked with fish for angling. On the day we visited there were more birds fishing than anglers!
The site boasts a comprehensive bird list, 147 species listed so far in about seven years or so. In winter there are large numbers of wildfowl and it is easy to see the potential and good records often crop up on the Dorset Bird Club list from here. In summer the lakes are surrounded by rushes and reeds and there are lots of wild flowers which, in turn means lots of insects.
Apart from the noise from the nearby busy road it is a pleasant and interesting walk that takes about 1.5 hours at a leisurely pace. Lots to see at any time of year and I fully recommend a visit. There is something special about sites with water present.