Pen y Fan same noun "ban", in its plural form "bannau", is found in the Welsh name for the Brecon Beacons: "Bannau Brycheiniog". There is no one standard translation of "Pen y Fan", but 'the mountain's peak' or 'the beacon's summit' are both possible translations. Pen y Fan is formed from various units of the Old Red Sandstone which were laid down during the Devonian period. The lower slopes of the mountain are formed from the sandstones and mudstones of the Senni Formation whilst the upper slopes are formed from those of the Brownstones Formation. The very summit, like that of neighbouring Corn
Tal y Fan Tal y Fan Tal y Fan is an outlying peak of the Carneddau mountains in North Wales. It is one of the four Marilyns that make up the Carneddau, the others being Carnedd Llywelyn, Pen Llithrig y Wrach and Creigiau Gleision. It is high, and lies midway between the Conwy valley to the east and Penmaenmawr on the coast to the north-west. It is the most northerly 2000 ft summit in Wales. On 6 May 2013 BBC News reported that a precise GPS measurement of Tal y Fan's height had been verified by the Ordnance Survey as 609.98 metres or