Holy Island, also known as Lindisfarne, is a small and remote tidal island located several miles off the Northumberland coast. The causeway linking it to the mainland is cut off twice-daily by fast-moving tides. It is famed for being a significant centre of Celtic Christianity and as the first place in the British Isles to be invaded by Vikings in 793. Visitor attractions include the remains of a 12th century priory and a Tudor built fort.