The northern and western portions are, however, less arid than the east and south, being watered to some distance by the streams that descend from Zagros and Elburz, and deriving fertility also from the spring rains.

Some of the rivers which flow from Zagros on this side are large and strong.

One, the Kizil-Uzen, reaches the Caspian.

Another, the Zenderud, fertilizes a large district near Isfahan.

A third, the Bendamir, flows by Persepolis and terminates in a sheet of water of some size--lake Bakhtigan.