Start Tretower (AA call box), proceed westwards on A40, TURN Brecon East RB and re-trace, turn left Bwlch onto B4560, pass through Llangors and Trefecca (both 20mph zones), turn right Talgarth South RB onto A479, past summit of climb at Pengenffordd through Cwmdu, to finish on A479 at junction with bridleway on left from Efail Isaf, 200yds before Tretower 20mph zone. 33.5 miles approx..