The "fertile crescent", or "cradle of civilization" refers to which river valley civilization?

The "fertile crescent" refers to the area between the Tigris and Euphrates rivers where early civilization is believed to have grown.

Explanation:

This region between the Tigris and Euphrates rivers was formerly known as Babylon. It also includes the Levant which is the eastern coast of the Mediterranean.

Many of today's nations that had territories in the fertile crescent include Iraq, Syria, Lebanon, Cyprus, Jordan, Israel Palestine, Egypt, and portions of Turkey and Iran.