The Mahon Valley Mahon Falls and Knockaunapeebra from the saddle on Comeragh Mountain The Mahon Valley is unquestionably one of the most dramatic and scenic places in the Comeraghs. Driving up the valley from Mahon Bridge at the bottom to Mahon Falls at the top you find yourself growing ever more enchanted by the awe-inspiring vistas of this magnificent glacial valley. Better still, why not walk up along the Crough Wood Trail for a while and then continue to the top on the winding road to take in the many features of this magnificent valley? Glaciated Valley Par Excellence Along with the Nire Valley the Mahon Valley is considered to be one of the best examples of a glaciated valley in the Comeraghs. It is over 3 kilometres long, 600 to 800 metres wide, and stretches from Mahon Falls in the north to Crough Wood and Croagh Hill near Mahon Bridge in the south. It drops in elevation from about 400 metres at the Falls to 200 metres at the mouth and possesses the classic u-shaped profile o