If you are coming from the London or further north, then head down the M20 to Junction 10 and take the A2070 in the direction of Lydd (although I can't remember what it is signpotsed as). Pick up the A259 at the roundabout towards the end of the A2070 and this is the Rye/Hythe road. Follow this road until you come across the B2075 that is signposted to Lydd and Lydd Airport. You go pass the airport (on your left) and then head over a small bridge on the entrance to Lydd itself.
Immediately after the bridge is a left-hand turn that takes you down to a roundabout. Go straight over this roundabout and take the first slip road on the left. Go down this road for another 1 mile (approx.), following the signs for the Windsurfing school. Eventually the road becomes more of a track than a road and on the right you will see the Leisure Park. The circuit is part of this complex and is signposted once inside the complex