Like Camelot or Shangri-La, Lindisfarne has a magical name, yet it is a real place, amid the beautiful Northumberland Coast — AFTER visiting the Farne Islands, I drove to Lindisfarne, the ancient monastic retreat that is also known as Holy Island, the Holy Island, or, as in this road sign, the Holy Island of Lindisfarne, a name that removes all confusion. Here is a map, which shows the Farne Islands in…