Corn Du is pronounced "Corn Dee" and is translated as "black horn". It is slightly smaller than its neighbour, Pen-Y-Fan, which is the highest peak in southern Britain but at 873m is a close second. It is joined to Pen-Y-Fan but there is sufficient distance and loss in elevation for it to be clearly a mountain in it’s own right. The summit is large and flat, like the cairn upon it but the views are breathtaking.
The summit lies upon Old Red Sandstone and past glacial activity has produced a quite dramatic ridge to the North looking down on to photogenic Llyn Cwm Llwch, a near-circular tarn formed by an ice tributary of the main glacier. To the Southeast, lies a deep glacial valley that contains the less natural Upper Neuadd Reservoir.
The mountain is in the Brecon Beacons National Park and is an area of natural beauty and unexpectedly dramatic scenery for South Wales. The most southerly part of Powys, close to the Market town of Brecon (now famous for Brecon Jazz) and historically important town of Merthyr Tydfil.
Llyn Cwm Llwch
It is easily accessible from the M4 and nearby Cardiff, there are a few routes but the most obvious and easiest is to get a bus or to park in the car Park opposite to the Storey Arms Outdoor Education Centre, run by Cardiff Council. The summit can be reached in under an hour, and the views are spectacular once the ridge has be reached. It would be remiss not to mention that it is hellishly busy in the summer months, when the path expands in width due to the trampling feet and leaves a nasty scar. Fortunately this has improved recently with path improvements and foot and mouth.
The ease of accessibility and walking combined with the great views means this is an incredibly popular mountain.
Red Tape and Weather
Although an easy undertaking, the weather does need to be considered. In the beacons the weather is changeable and the cloud base is frequently low. This is hardly life threatening but can leave you wet and miserable with grey photographs.
Typical Beacons weather