The Indus Valley civilization flourished between 2600-1900 BC along the Indus River valley. At its peak, it had over 5 million inhabitants living in well-planned cities like Harappa and Mohenjo-Daro, which featured advanced architecture including water and sewage systems. The civilization engaged in extensive trade and developed new techniques in metallurgy. While much remains unknown about the Indus Valley civilization, archaeologists have uncovered artifacts that provide insights into its writing system, religious practices, and material culture, including tools, clothing, and pottery.