This is one of Ireland’s smallest medieval cathedrals, but it was once one of the most important in Leinster. It’s now regarded as one of the finest 12th-century cathedrals in Ireland. Founded in 632 by Saint Lazerian, the current building mostly dates from 1181, although there have been many additions since then. They include the tower and the north chapel. Highlights include a four-bay sedilia from the 13th century, probably unique in Ireland, an 11th-century font. Guided tours are available by prior request.