The Bronze Age in the Indus Valley began around 3300 BCE with the Indus Valley Civilization. Along with Ancient Egypt and Mesopotamia, it was one of three early civilizations of the Old World, and of the three the most widespread, covering an area of 1.25 million km2. It flourished in the basins of the Indus River, in what is today the Pakistani provinces of Sindh, Punjab and Balochistan, and along a system of perennial, mostly monsoon-fed, rivers that once coursed in the vicinity of the seasonal Ghaggar-Hakra River in parts of north-west India. At its peak, the civilization hosted a population of approximately 5 million spread across hundreds of settlements extending as far as the Arabian Sea to present-day southern and eastern Afghanistan, and the Himalayas. Inhabitants of the ancient Indus river valley, the Harappans, developed new techniques in metallurgy and handicraft (carneol products, seal carving), and produced copper, bronze, lead, and tin.