O’r awyr O’r awyr 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 Twll 1 Twll 2 Twll 3 Twll 4 Twll 5 Twll 6 Twll 7 Twll 8 Twll 9 Twll 10 Twll 11 Twll 12 Twll 13 Twll 14 Twll 15 Twll 16 Twll 17 Twll 18