The Amu-Darya delta, stretching southeast of Urgench to the Aral Sea, has been inhabited for millennia and was an important oasis long before Urgench or even Khiva were important. What the Nile is to Egypt, the Amu-Darya has been to Central Asia. The historical name of the delta area, which includes parts of modern-day northern Turkmenistan, was Khorezm.
Today Khorezm (Xorazm) district takes in the former khanate of Khiva, the border region with Turkmenistan and the Soviet-era city of Urgench. Historically Khorezm also included the collection of ancient desert cities now collectively known as the Ellik Kala (Fifty Fortresses). Today, these are technically in Karakalpakstan, but are most commonly visited from Khiva.