The Zenderud or river of Isfahan rises from the eastern flank of the Kuh-i-Zerd (Yellow Mountain), a portion of the Bakhti-yari chain, and, receiving a number of tributaries from the same mountain district, flows with a course which is generally east or somewhat north of east, past the great city of Isfahan—­so long the capital of Persia—­into the desert country beyond, where it is absorbed in irrigation.  Its entire course is perhaps not more than 120 or 130 miles; but running chiefly through a plain region, and being naturally a stream of large size, it is among the most valuable of the Median rivers, its waters being capable of spreading fertility, by means of a proper arrangement of canals, over a vast extent of country, and giving to this part of Iran a sylvan character, scarcely found elsewhere on the plateau.

It will be observed that of these streams there is not one which reaches the ocean.  All the rivers of the great Iranic plateau terminate in lakes or inland seas, or else lose themselves in the desert.  In general the thirsty sand absorbs, within a short distance of their source, the various brooks and streams which flow south and east into the desert from the northern and western mountain chains, without allowing them to collect into rivers or to carry fertility far into the plain region.  The the river of Isfahan forms the only exception to this rule within the limits of the ancient Media.  All its other important streams, as has been seen, flow either into the Caspian or into the great lake of Urumiyeh.

That lake itself now requires our attention.  It is an oblong basin, stretching in its greater direction from N.N.W. to S.S.  E., a distance of above eighty miles, with an average width of about twenty-five miles.  On its eastern side a remarkable peninsula, projecting far into its waters, divides it into two portions of very unequal size—­a northern and a southern.

The southern one, which is the largest of the two, is diversified towards its centre by a group of islands, some of which are of a considerable size.  The lake, like others in this part of Asia, is several thousand feet above the sea level.  Its waters are heavily impregnated with salt, resembling those of the Dead Sea.  No fish can live in them.  When a storm sweeps over their surface it only raises the waves a few feet; and no sooner is it passed than they rapidly subside again into a deep, heavy, death-like sleep.  The lake is shallow, nowhere exceeding four fathoms, and averaging about two fathoms—­a depth which, however, is rarely attained within two miles of the land.  The water is pellucid.  To the eye it has the deep blue color of some of the northern Italian lakes, whence it was called by the Armenians the Kapotan Zow or “Blue Sea.”