Diarmait Mac Murchada built Baltinglass Abbey in 1148. He is better remembered for what he did twenty years later.
The man who founded the abbey and the Normans
Diarmait Mac Murchada, King of Leinster, founded Baltinglass Abbey for the Cistercians in 1148, shortly after the order established its first Irish house at Mellifont. Church reformers of the time regarded Diarmait as an ally - he built abbeys, he supported the reform movement. In 1166, a coalition of Irish kings expelled him from Leinster after a long-running dispute over his abduction of Dervorgilla, wife of Tiernan O'Rourke of Breifne. Diarmait crossed to Bristol and appealed to Henry II of England for military help. The Anglo-Norman mercenaries who landed in Ireland in 1169 at his invitation changed the country for the following eight hundred years. The ruins of the abbey he built before any of that stand on the north side of Baltinglass, freely accessible, without a visitor centre or an entry fee.
A Cistercian church built in 1148 that was still occupied in 1536.
What the abbey is, and what survives
The Cistercians were an austere order who built spare, functional architecture - no decoration for its own sake, no vanity stonework. Baltinglass Abbey's church is 56 metres long, with a nave, aisles, chancel, and a pair of transepts. The six Gothic arches on alternate round and square pillars are the feature most people remember. Some of the cloister to the south has been rebuilt. The east windows and tower are 19th-century additions. The abbey was occupied for nearly four hundred years before the Dissolution of the Monasteries in 1536 shut it down. It is today a National Monument, which means the OPW maintains it and anyone can walk in.
A Neolithic cairn older than Newgrange, two kilometres from town.
The passage tomb on Baltinglass Hill
Rathcoran, the passage tomb on the summit of Baltinglass Hill, was excavated in the 1930s and later subject to detailed radiocarbon dating that placed its construction at around 3600-3400 BC - roughly contemporaneous with Newgrange, possibly slightly earlier. The cairn is 27 metres in diameter and covers at least five separate structures. The main tomb has a three-metre passage with roof slabs still in place, leading to a chamber with three narrow compartments and a basin stone. The finds included the cremated remains of at least three adults and a child, flint scrapers, and carbonised wheat grains and hazelnuts sealed under the cairn. A double-rampart Iron Age hillfort - also called Rathcoran - was built around the cairn centuries later, using the Neolithic monument as its centre. The hill is two kilometres east of town and the walk to the summit takes about an hour.