Northburgh Castle, also known as Green Castle or Greencastle Castle, is a 13th/14th-century ruin in Greencastle, Ireland. Completed in 1305 by Richard Óg de Burgh, it controlled Lough Foyle and served expansion plans. Edward Bruce captured it in 1316, and it later became an O'Doherty stronghold. The castle features an oval enclosure with a twin-towered gatehouse and a later large tower. Influenced by Edward I, it symbolized a shift from pure military structures to administrative centers. Damaged by cannon fire, the castle is now managed by the Irish government and accessible from the town and shore.
Saint-Georges de Boscherville Abbey is a former Benedictine abbey. It was founded in about 1113 by Guillaume de Tancarville on the site of an earlier establishment of secular canons and settled by monks from the Abbey of Saint-Evroul. The abbey church made of Caumont stone was erected from 1113 to 1140. The Norman builders aimed to have very well-lit naves and they did this by means of tall, large windows, initially made possible by a wooden ceiling, which prevented uplift, although this was replaced by a Gothic vault in the 13th century. The chapter room was built after the abbey church and dates from the last quarter of the 12th century.
The arrival of the Maurist monks in 1659, after the disasters of the Wars of Religion, helped to get the abbey back on a firmer spiritual, architectural and economic footing. They erected a large monastic building one wing of which fitted tightly around the chapter house (which was otherwise left as it was).