 Battery Rocks have been a location for winter swimmers from at least the 1880s as was mentioned in an 1881 edition of The Cornishman newspaper, which described the practice of the annual Boxing Day swim being enjoyed by the ″all-year-round″ bathers.The rocks are on the northern shore of Mount's Bay, and along with the headland, provide shelter for Penzance harbour from the prevailing south-west winds.A rock on the most easterly point is called Carn Olven and on the western side are the Chimney Rocks.