Inside the central door of Iona Abbey and to the immediate left is a tiny room tucked into the corner. A discreet flight of stone steps leads up to what is in essence a cubbyhole containing nothing but a single squat chair which looks barely suitable for even a child. So low is the lintel, I had to enter the room on my belly. It has a window like an archers slit allowing whomever is inside to see not only the main entrance but also the nearby nunnery and in the distance, the island’s main dock. I learned that this was intentional, of course: at the height of Iona’s ecclesiastic importance the room was manned by a sentinel around the clock, so that anyone seeking out the abbey would be sure to be greeted. As I crawled out feet first I noticed a reminder carved into the small door: stand fast.