Clonmacnoise, the medieval crossroads of Ireland

Clonmacnoise is one of Ireland's most significant monastic sites.  Located on a bend of the River Shannon, once a major transportation  route, the monastery was founded in 545 AD by St. Cieran and built on an esker, a natural granite ridge. Its earliest remains are from the 9th century. From this period onward, it was routinely plundered by the Irish, Vikings and Anglo-Normans, and ultimately destroyed by the British in the mid-16th century.