start on a.26 one mile south of tonbridge, at kerb point 50 yards north of mabeldon and 10 feet past 40 mph limit signs (tq580445). proceed north and take first left to join a21. proceed on a.21, left on slip road to weald roundabout using the left hand side of the carriageway. (5.4 miles). encircle and retrace on a.21 to finish at the leading edge of the last bridge before the a.26 slip road (tq575451).