Take the A3057 (Stockbridge Road) to King Somborne before turning on to Cow Drove Hill.  At the top of the hill turn left and follow the road until to turns in to a track.  Continue on the track bearing round to the right when you can go no further between two gate posts and on to a gravel track.  Continue on this until you can go no further (in a car) where you will see the entrance to the lakes on your left hand side.