Dorset: Durdle Door on the Isle of Purbeck, near Poole. (It's not actually an island, it's part of the mainland.)
Durdle Door Dorset
You'll also have Lulworth Cove, Swannage, Stair Hole, and Corfe Castle nearby with good views of The Blind Cow, and Bat's Head from Dungy Head. A very pleasant part of the world.
Pete.