start on a603 at point marked on kerbstone in entrance to mrao site west of barton near milestone "cambridge 5 miles". proceed westwards on a603 through orwell to wimpole rab junction with a1198, straight on to continue on b1042 westward through tadlow to near wrestlingworth, continue westward on unclassified road through eyeworth and dunton to:- turn at dunton rab and retrace outward route to:- finish on a603 at point marked on road edge east of milestone "cambridge 5 miles" near start.