sentences:  Although small scale, Banc Du has profound implications for the understanding of occupation of the area in the fourth and third millennia BC.The first confirmed neolithic enclosure in Wales and the mid west of Britain, it is also notable for the fact that visible earthworks survive at ground level.When first built, it would have been contemporary with the great megalithic tombs such as the long barrow at Pentre Ifan just 7.5 km to the north, and the passage grave at Bedd yr Afanc 6 km to the north-east.