Swords Castle is the best surviving example of an archbishop's palace in Ireland, built around 1200 by the Archbishop of Dublin, John Comyn. The castle features a unique polygonal enclosure with curtain walls that enclose over an acre of land sloping to the Ward River. Originally serving as the principal episcopal seat with ecclesiastical court functions, it was expanded in the 14th century to include a large banqueting hall and chapel. The National Monument represents medieval engineering and over 800 years of monastic and ecclesiastical history.