The Indus Valley Civilization was noted for its advanced city planning and trade, flourishing around 2500 BCE in present-day Pakistan and northwest India. Cities like Harappa and Mohenjo-Daro featured sophisticated grid patterns, advanced drainage systems, and brick buildings, showing a high level of urban infrastructure. The civilization engaged in long-distance trade with neighboring regions, including Mesopotamia, evidenced by the discovery of seals and goods exchanged. Their economy was diverse, relying on agriculture, crafts, and trade, and they developed a writing system that remains undeciphered. The Indus Valley represents one of the earliest examples of urban life in human history.