This is a fine route offering a variety of terrain and views. Much of it is on tracks with few navigation difficulties.
It leaves the car park by the Shay Elliot memorial and follows a series of forest roads SW downhill towards Drumgoff, picking up the Wicklow Way, before turning NW and rising into Glemalure. It gives some splendid views across Glenmalure including Carrawaystick Waterfall, the Zig Zags, Clohernagh and Lugnaquilla, if it is not shrouded in mist.
Continue on the WW out onto open land crossing the Mullacor Gap. Views of Mullacor, Lugduff and more, before re-entering forest and descending almost to the floor of Glendalough. More forest interspersed with views across Glendalough.
Make the steep but short ascent to the Derrybawn ridge. This is often windswept and always soggy but on a clear day offers some of the most splendid scenery in Wicklow. Make your way SW to the end of the ridge pausing to admire the scenery,and then SE and East to Cullentragh.
Cullentragh is well worth a visit so don't be tempted to bypass it. From Cullentragh head SE for the 20 min walk back to the Shay Elliot. Distance 18 km, ascent 750 m, walking time 4 to 4.5 hours.