I visited Clonmacnoise on the most spectacular day in June. It was sunny and bright and also very windy but certainly the ideal day to visit this amazing historical site. Located right on the River Shannon (you can see it here in the background), Clonmacnoisse is an early Christian site founded in the mid-6th Century by St. Ciaran. The Irish is Claun Mhic Nos 'meadow of the sons on Nos'.
The site includes the ruins of a cathedral, seven churches (10-13th century), 2 round towers, 3 high crosses and the largest collection of Early Christian graveslabs in all of Western Europe.
The central focus on the settlement was, of course, religion but it also served as a centre for politics, learning trade and craftsmanship. Unfortunately many of the houses and early churches were made of wood, so they have not survived but there is a comprehensive visitor centre with a video detailing the history, replicas of some of the buildings and other examples of life in the settlement.
The Cross of the Scriptures (c. 900 AD) this is actually a replica but the original is housed inside the visitor centre.
Details from The Cross of the Scriptures.
The Whispering Arch.
There is a cafe on the premises which is fine for a simple lunch. Otherwise there is nothing right nearby so pack a lunch or plan to travel further away to find a spot to eat - it is about half and hour from Athlone.