 Commonly, they are found in Northern Germany at the coasts of the North and Baltic Seas.In Britain they are also called hag stones, witch stones, serpent's eggs, snake's eggs, or Glain Neidr in Wales, milpreve in Cornwall, adderstanes in the south of Scotland and Gloine nan Druidh ("Druids' glass" in Scottish Gaelic) in the north.In Germany they are called Hühnergötter ("chicken gods").