The biggest achievements of the Indus Valley civilisation were Harappa and the city of Mohenjo-Daro. These cities are well-known for their stunning, well-organized, and consistent layout. They feature an efficient plumbing and drainage system, as well as indoor toilets. The people of this culture built using stone, bone, and clay tools. They made weapons from bronze and iron. Evidence suggests that the Harappans traded with peoples as far away as Afghanistan and Iran. The culture lasted from 3000 to 600 B.C. In contrast to other ancient civilizations, such as those in Egypt or Mesopotamia, there is little evidence of a powerful ruler or army during the time of the Harappans. It seems they lived in small independent towns that may have been ruled by local elites who probably inherited their position. There is no indication of warfare between these cities, although it's possible that they fought tribal wars outside the region. In addition to cities, the Harappans also constructed large scale irrigation systems. These can be seen today in the Faisalabad region of Pakistan, where the engineers who maintain them live. The Harappans used natural waterways for irrigation, but also built many large reservoirs for additional water storage. Their canals were not just for farming, but for transportation as well. Some were even able to carry water from one end of the valley to another.