Mount San Michel is a medieval town called Avranches. The monastery, which gives the place it's name was fortified in the thirteenth century, with three cities whose fortifications and development are remarkable: Aigues Mortes (1270-1276), Carcassone, and Avignon (1309-1377). These fortified cities, called "bastides" marked the frontier of the kingdom at the end of the Middle Ages. More than 300 were built in France alone, between 1220 and 1350.
St Patricks Cathedral, Dublin - current building erected 1220-1270 AD - on site of Irish people's baptism by St. Patrick in 450 AD - earliest mention of a church on this site was in 890 AD - largest cathedral in Ireland