In light of recent discoveries in the Boyne Valley, we are particularly enthused about returning here for a day seminar to explore the Neolithic passage tombs of Newgrange, Knowth, Dowth and the wider landscape. Emphasis is placed on this extensive Neolithic (3300–3000 BC) passage tomb cemetery at the Bend of the Boyne, which includes the three largest artificial structures in Neolithic Europe (each 80 metres (262 ft) in diameter and containing about 200,000 tonnes of material). In addition to their use as burial places the tombs were the focus of an elaborate ‘Cult of the Ancestors’. Long after its prehistoric abandonment the Knowth mound was fortified and became the residence of the kings of North Brega, one of the most powerful new families of the Uí Neill (O Neill) dynasty descended from the legendary founder Niall Noígiallach (‘Niall of the Nine Hostages’).