Some beaches are covered in fine sand. Others are muddy, and some are made entirely of pebbles – shingle. It all depends on the waves.
If you walk around a bay, you will find that the beach material is finer in the shelter of the headland, and shingly in more exposed regions.
This is because, in storms, exposed parts of the bay are pounded by giant waves, and only shingle is heavy enough to stop getting washed away.
