The Indus Valley Civilization existed from 3300 to 1300 BCE in the northwestern region of South Asia, where it stretched across Pakistan, India, and Afghanistan. At its height, the Indus Valley Civilization might have had a population of up to five million. Ancient Indus cities were known for their brick houses, water supply systems, non-residential buildings, urban planning, and handicraft techniques. The cities of the Indus had their own social hierarchies and writing systems. They are believed to have spoken the Harappan language, which still has not been deciphered. The first modern account of the Indus Civilization are those of Charles Masson, who discovered the ruins of Harappa in Punjab, Pakistan.
