The Indus Valley
Located in what is currently known as Pakistan, the Indus Valley was a very popular area that could have possibly housed about five million people. This was one of the greatest civilization in the ancient world. It was also known as Harappan civilization. According to research, the place was abandoned more than three thousand years ago. It still boasts of grand walkaways, metallurgy shops and even multistory brick houses. The actual reason why the civilization disappeared is not known and will possibly never be. The most possible cause would be a change in weather patterns that made it hard for the people to grow food crops thus moving to other lands.