sentences:  Banc Du
  
  Banc Du is a prominent, fairly flat-topped southwards-projecting promontory of Foel Eryr, at about 334m OD at the west end of the Preseli Hills in north Pembrokeshire, Wales.First spotted during an aerial photographic survey of the region in 1990, this hilltop enclosure consists of two non-concentric and incomplete earthworks that define a roughly oval area around the hilltop, amidst a series of cultivation features and abandoned trackways.