GIANT'S KETTLE, GIANT'S CAULDRON, a glacial pot-hole, i.e., a deep cylindrical hole in solid rock drilled out by eddying currents of water of sub-glacial streams, bearing stones, gravel and other detrital matter. The size varies from a few inches to several feet in depth and diameter and upon the retreat of the ice, the whole frequently contains the sand, gravel or boulders which have assisted in its formation. Good examples occur in the Alps (Lucerne), Germany, Norway and U.S.A. These must not be confused with true pot-holes which occur in river beds and at the base of sea cliffs.