Cupstone

Cupstones, also called anvil stones and nutting stones, are lithic artifacts having a roughly discoidal surface resulting from human action. The hemispherical indentation itself is an important element of paleoart, known as a "cupule". Cup and ring marks are also common in the Fertile Crescent and India, and later in the Mediterranean, Atlantic, and Alpine regions of Europe, sometimes associated with complex petroglyphs or megalithic monuments.