Greece has its sun-soaked Cyclades and Dodecanese, Scotland its Northern Isles and rain-drenched Hebrides and Ireland the Arans and Skelligs. And what has England got? The isles of Canvey, Sheppey, Wight and Dogs, Mersea, Brownsea, Two Tree and Rat. But there are also wilder, rockier places - Lundy, the Scillies, Holy Island, the Farnes.