Lihou Island, the most western of the Channel Islands, seen from Guernsey.
Lihou Island, which is about a half of a mile from Guernsey, can be reached on foot during low tide periods: a causeway links it to the mainland. There's a lot of nonsense about stout footwear being needed to make the crossing, although anyone making the twenty-minute effort, while not needing wellingtons, should be prepared for wet feet: the causeway isn't entirely continuous, and the (slightly) adventurous have to contend with rather slippery seaweed (once a part here of the iodine industry). Apart from Victor Hugo's Hauteville house and the Little Chapel, this must rank as the third Guernsey must: and it's free! (In The Book of Ebenezer le Page (1981), G. B. Edwards mentions the childhood days of Ebenezer and his friend Jim, who get stranded on the island and spend the night there.)
Part of the remains of the twelfth century Benedictine Priory here.