Where were the world earliest civilizations located?

The world's earliest civilizations emerged in fertile river valleys, notably in Mesopotamia between the Tigris and Euphrates rivers, around 3500 BCE. Other significant early civilizations developed along the Nile River in Egypt, the Indus River in present-day Pakistan and northwest India, and the Yellow River in China. These locations provided abundant resources and fertile land, facilitating agriculture, trade, and the rise of complex societies.