Lindisfarne is a truly wonderful place. It is reached by a tidal causeway, and visiting times are totally dependent on tides. As soon as you arrive there, the peace is palpable. There is a small village next to a ruined monastery. The monastery was founded by St Aiden in 635AD when he came from Iona.
There is also a castle there, built on a volcanic mound using the stones of the abbey following its destruction in the dissolution of the monasteries by King Henry in the 1550s. It was converted into a beautiful home by Sir Edwin Lutyens.