The Brecon Beacons are a mountain range in Wales. The range includes South Wales's highest mountain, Pen y Fan, its twin summit Corn Du, and Craig Gwaun Taf, which are the three highest peaks in the range. The Brecon Beacons have given their name to the larger Brecon Beacons National Park, and the range itself is therefore sometimes known as the Central Beacons to differentiate the two.

Pen y Fan is the highest peak in South Wales, situated in Brecon Beacons National Park. At 886 metres (2,907 ft) above sea-level, it is also the highest British peak south of Cadair Idris in Snowdonia. It is the highest point of the historic county of Brecknockshire. The twin summits of Pen y Fan and Corn Du at 873 metres (2,864 ft) were formerly referred to as Cadair Arthur or 'Arthur's Seat'.