Founded by St Kieran (Ciarán), Clonmacnoise monastery was the burial place of the kings of Connaught and Tara and the largest and richest monastery of Ireland. Most of the vestiges date back to a period from the 10C-12C and give an idea of how the monastery was organised at the time. Surrounded by stone walls, it was made up of eight churches, a cathedral, two round towers, tombs and three large crosses. A pilgrimage takes place here on 9 September.