The name Amu is said to have come from the medieval city of Āmul , ( later , Chahar Joy\/Charjunow , and now known as Türkmenabat ) , in modern Turkmenistan , with Darya being the Persian word for `` river '' .
The name Amu is said to have come from the medieval city of Āmul , ( later , Chahar Joy\/Charjunow , and now known as Türkmenabat ) , in modern Turkmenistan .