Around 5,000 years ago, a civilization developed along the Indus River Alluvial Plain. In the text, it says that "Over time, a vast number of settlements were built on the banks of the Indus River and surrounding areas." Additionally, the Indus Valley region was rich with fertile soil, which is very ideal for Agriculture, also the Indus plain is surrounded by high mountains, desert, and ocean, perfect for a settlement, indeed.