A mile south of Helston is Loe Pool, Cornwall’s largest freshwater lake, said by some to be the resting place of King Arthur’s magical blade, Excalibur. It's cut off from the sea by the treacherous sandbank of Loe Bar – scene of many a shipwreck down the centuries. Walking trails wind their way around the lakeshore and the surrounding Penrose Estate, but swimming is dangerous due to unpredictable rip currents.