Geograph - photograph every grid square

The very summit of Y Fal (Sugar Loaf) is formed from Quartz Conglomerate - the youngest rocks of the Old Red Sandstone or 'O.R.S.' It is the ORS which forms the dramatic hills of the Black Mountains and Brecon Beacons. From the west end of the summit ridge can be seen Pen Cerrig-calch on the right sloping down to the hillfort of Crug Hywel SO2220 (which gives its name to the nearby village of Crickhowell). Beyond the hazy Usk valley can be seen the summit of Pen y Fan.