HOW DID THE VIKING RAIDERS FIND THE MONASTERIES? Gareth Williams, a Viking expert at the British Museum, is quoted in the Archaeology article in support of the theory that Viking traders came to Ireland generations before the Viking raiders: “How did the Vikings know where all those monasteries were? It’s because there was already contact. They were already trading before those raids happened.”
I had heard a different explanation in connection with our visit to Saint Kevin’s Church and the Round Tower at Glendalough. We asked an Irishman about the Viking success in raiding monasteries and he pointed out that the monks advertised their monasteries with buildings that could be seen from a great distance.
Here is a wikipedia entry on Saint Kevin, who lived from 498 to 618. There is a picture of the church and the tower.