Resting somberly on the east bank of the Shannon, this is one of Ireland’s most profound ancient sites. St. Ciaran founded the monastic community of Clonmacnoise in 548 at the crucial intersection of the Shannon and the Dublin-Galway land route, and it soon became one of Europe’s great centers of learning and culture. For nearly 1,000 years, Clonmacnoise flourished under the patronage of Irish chiefs; the last high king, Rory O’Connor, was buried here in 1198. Clonmacnoise was raided repeatedly by native chiefs, Danes, and Anglo-Normans, until it was finally destroyed by English troops in 1552. Previously the monks always had something to rebuild, but this time the English looted everything. By the time they’d finished, according to a report written by a monk from that time, “There was not left a bell, small or large, an image or an altar, or a book, or a gem, or even glass in a window, from the wall of the church out, which was not carried off.” Today you can see what was left of the cathedral, a castle, eight churches, two round towers, three sculpted high crosses, and more than 200 monumental slabs. On some stones, the old carvings can still be seen with thoughtful messages in ancient Celtic, saying things like, “A prayer for Daniel.”