Pen y Fan () is the highest peak in South Wales, situated in the Brecon Beacons National Park. At above sea-level, it is also the highest British peak south of Cadair Idris in Snowdonia. It is the highest point (county top) of the historic county of Brecknockshire (though in modern administrative terms, it now lies within the unitary council area of Powys). The twin summits of Pen y Fan and Corn Du at 873 m (2,864 ft) were formerly referred to as Cadair Arthur or 'Arthur's Seat'. The mountain and surrounding area are owned by the National Trust whose work parties attempt to combat the erosion caused by the popularity of this peak with walkers. The mountain is used by the military as part of the selection process of the UK's Special Forces personnel. Three soldiers who died after collapsing in the field in July 2013 were taking part in a test march called Point-to-Point while undergoing Special Air Service selection. Name The name Pen y Fan consists of the Welsh words pen ('top, head, peak, summit', etc.), y ('the') and fan, a mutated form of ban ('summit, crest, peak, beacon, hill, mountain', etc.). 'The mountain's peak' or 'the top of the summit' are both possible translations. The noun ban, in its plural form bannau, is found in the Welsh name for the Brecon Beacons: Bannau Brycheiniog. In earlier times, Pen y Fan itself was sometimes called the '(Brecknock) Beacon'. In the General View of the Agriculture of the County of Brecknock (1794), John Clark of Builth (steward to Viscount Hereford) refers to 'the VANN, or Brecknock Beacon, the undisputed sovereign of all the mountains in South Wales'. On the tithe map for Cantref parish (1839), the peak of Pen y Fan is called 'Beacon'. This usage is no longer current. Access The peak is a major objective in the Beacons Way, a long distance footpath which passes from east to west across the massif, and is open to all walkers. There is a well made, evenly graded footpath from the Storey Arms on the A470, which is 1500 feet below. This and other paths on the mountain are the subject of ongoing repair and maintenance by the National Trust to limit the erosion caused by the passage of hundreds of thousands of walkers each year. There is also a major path from the Cribyn, a close-by peak to the