Paleolithic: It comes from two Greek words palaeo meaning old and lithos meaning stone. The palaeolithic period extends from 2 million years ago to about 12,000 years ago. Mesolithic period began about 12,000 years ago till about 10,000 years ago. Stone tools were found during this period Neolithic age began around 12,000 years ago andended as civilization started to rise around 3500 BCF. Megalithic are in general constructions erected during the Neolithic or late stone age and Chalcolithic or copper age (4500 - 1500 BC)