The Great Mound of Knowth is an impressive prehistoric passage tomb in the Boyne Valley, County Meath. It is the largest of the three major tombs in the Brú na Bóinne complex, which has been on the UNESCO World Heritage List since 1993.
Built around 3200 BC, making it older than the pyramids of Giza and Stonehenge, Knowth has two independent passages (east and west) that each lead to a separate chamber. The main mound is approximately 12 meters high and has a diameter of 67 meters. The large mound is surrounded by 17 or 18 smaller satellite tombs.
After the Neolithic period, the site remained in use. In the early Middle Ages, the top of the mound served as a royal residence for the kings of North Brega. Archaeological excavations since 1962 have also found evidence of Viking raids and habitation by Norman knights.