I have always had fun clambering over these rocks at Battery to get on the island and be 'King of the Castle'. I remember that when I was a kid, there used to be a kind of sea anemone I have never seen before or since which had black and pinkish-white tentacles ('Halcampa chrysanthellum' (Peach) perhaps!) and which you only saw in the rock pool on top of the island.
