Ireland's first Cistercian abbey, 1142
Mellifont
Malachy of Armagh — the saint and reformer who tried to bring the Irish church into line with continental practice — visited Bernard of Clairvaux in 1140, was given Cistercian monks, and brought them back to the Boyne. The land was granted by Donough O'Carroll, King of Airgialla. Mellifont became the mother house of all later Cistercian foundations in Ireland — thirty-five abbeys descended from it, including Bective, Boyle and Holy Cross. At its medieval height it housed about a hundred choir monks and three hundred lay brothers, and the abbot sat in the Irish Parliament. Henry VIII suppressed it in 1539; the buildings were granted to Edward Moore and remodelled as a fortified house, then knocked. The OPW manages what survives — the octagonal lavabo (the washing-house, c.1200, the photograph everyone takes), the chapter house, the crypt, fragments of the Romanesque cloister arcade. The 12th-century work is the oldest dressed stone in Co. Louth still in place.
1 July 1690 (12 July new style)
The Battle of the Boyne
William III of Orange, with about thirty-six thousand men, faced his father-in-law James II, with about twenty-five thousand, across the Boyne at Oldbridge on 1 July 1690. William's army crossed the river at three places — at Slane upstream, at Oldbridge in the centre, and at Donore — and rolled the Jacobite line up the slope to the south. James lost the day before noon, fled the field, and was on a boat to France within a fortnight. About two thousand men died — relatively light by European standards, but it was the symbolic battle that ended the Stuart claim to the British and Irish thrones. The OPW restored Oldbridge House (a 1740s mansion built on the battlefield) as the visitor centre; the battlefield walks pass through the actual ground the Williamite infantry advanced over. The Williamite cavalry forded the river through King William's Glen on the Tullyallen side, behind the village.
Francis Johnston, 1794
Townley Hall
Townley Hall is one of the finest neoclassical country houses in Ireland — Francis Johnston (architect of the GPO and Dublin Castle's chapel) built it in 1794–1799 for Blayney Townley Balfour. The plan is a perfect square around a top-lit cantilevered spiral stair, the kind of room architects come from England to look at. Trinity College Dublin owned it from 1958 to 2017 as a research and farm estate; it was sold privately in 2017. The house is not open to the public, but the demesne — sixty acres of parkland and woodland surrounding it — has long-standing public walking paths, and the Coillte-managed Townley Hall Wood and King William's Glen trails are part of the Boyne Valley walking network.
The GAA club
Glen Emmets
The village's GAA club is Glen Emmets — football only, fielding teams from under-7s to senior, named after Robert Emmet and the glen the Williamites rode through. The pitch is at the top of the village. The club is the Saturday-morning glue of the parish — if you ask in McDonnell's whether you should go to the abbey or the battlefield first, somebody will work out the answer based on whether there's a match on at three.