Knowth (Irish: Cnogba) is a Neolithic Passage Tomb located in the Boyne Valley, County Meath. Along with Newgrange and Dowth, it is part of the Bru na Bainne complex which is a UNESCO World Heritage Site. It is the largest passage grave of the complex and consists of a large mound and 17 smaller satellite tombs. The large mound is about 12 metres (40 ft) high and 67 metres (220 ft) in diameter and has been estimated to date from between 2500 and 2000 B…C. It contains two passages placed along an east-west line and is encircled by 127 kerbstones many of which contain megalithic art. In fact, Knowth contains more than a third of the total number of examples of megalithic art in all of Western Europe!
Interestingly, much of this artwork was carved onto the backs of the stones; a type of megalithic art known as hidden art. This suggests all manner of theories as regards the function of megalithic art within the monuments of Knowth. It is possible that they intended the art to be hidden. It is also possible that they simply recycled the stones and reused the other side. Many are thought to have associations with solar and lunar calendars. The tomb fell into disrepair during the Neolithic period when the mound or cairn slipped, causing the entrances to both passages to be covered. However, archeological evidence suggests that the site was used as a ritual or sacred area during the later Bronze Age, long after the great mound itself had fallen into disuse.
In the Dindsenchas (lore of places) of Cnogba, we are told that its proper name is Cnoc Bui, (the Hill of Bui). Bui was said to be the wife of the god Lugh; she was buried there and the great mound was constructed over her body. Bui is also thought to be a manifestation of the Cailleach or The Hag of Beara, an ancient Irish goddess. In one version of the tale, she was also the lover of Aengus Og (the god of love and youthfulness) who abducted her from a feast she was attending and brought her to the Sidhe (Palace) at Knowth which now bears her name. The Cailleach’s role in Irish tradition as an earth goddess, as well as her associations with death, make her (or Bui) an appropriate connection with Knowth.