Still farther south, towards Kerman, there are several peaks (Bid-Khan, Lalehzar, Shah-Kuh, Jamal Bariz, etc.) which rise to an elevation of 13,000 feet or more and the Kuh-i-Hazar, south of Kerman, is 14.700 feet in height. Beginning near Ardebil in Azerbaijan, where the cone of Savelan rises to an elevation of 15,792 feet (Russian trigonometrical survey), and ending in Khorasan, the great Elburz range presents on its southern or inward face a more or less abrupt scarp rising above immense gravel slopes, and reaches in some of its summits a height of nearly 13,00o feet; and the peak of Demavend, north-east of Tehran, has a height of 18,60o feet. There are several impor tant ranges in Khurasan, and one of them, the Binalud, west of Meshed and north of Nishapur, has several peaks of T i,000 to 12,000 feet in height. In south-eastern Persia the Kuh-i-Basman, a dormant volcano, ii,000 to 12,000 feet in height, in the Basman district, and the Kuh-i-Taftan, an active triple-peaked volcano in the Sarhad district, 12,681 feet in height, are notable features.
Of the surface drainage of the Iranian plateau as a whole less than half flows outwards. Taking the area occupied by Persia at 628,00o sq. miles the drainage may thus be distributed: (I) into the Arabian Sea and the Persian Gulf, 135,00o sq. miles; (2) into the Caspian, ioo,000; (3) into the Seistan depression, 43,00o; (4) into the Urmia Lake, 2o,000; (5) into the interior of Persia, 330,000. The first district comprises most of the south-western provinces and the whole of the coast region as far east as Gwattar ; the second relates to the tracts west, south and east of the southern part of the Caspian sea. The tracts south of the Caspian are not more than 20 to 5o miles wide; those on the west widen out to a depth of 25o miles, meeting the watershed of the Tigris on the one side and that of the Euphrates and Lake Van on the other, and embracing between the two the basin of Lake Urmia. On the east the watershed of the Caspian gradually increases in breadth, the foot of the scarp extending considerably to the north of the south-eastern angle of that sea, three degrees east of which it turns to the south-east, parallel to the axis of the Dagh. The third drainage area comprises Persian Seistan with part of the Helmund basin and a considerable tract adjoining it on the west. The fourth is a comparatively small area on the western frontier containing the basin of Lake Urmia, shut off from the rest of the inland drainage, and the fifth area takes in a part of Baluchistan, most of Kerman, a part of Fars, all Yezd, Isfahan, Kashan, Qum, Iraq, Khamseh, Kazvin, Tehran, Samnan, Damghan, Shahrud, Khurasan and the central desert regions.
Four rivers belonging exclusively to Persia, in reference to the Caspian watershed, are the Safid Rud or Kizil Uzain on the south west, the Herhaz on the south and the Gurgan and Atrek at the south-eastern corner of that inland sea. The Safid Rud rises in Persian Kurdistan in about 35° 50' north, and 46° 45' east, a few miles from Senendij. It has a very tortuous course of nearly 500 m. for the distance from its source to the Caspian, 58 m. east of Resht, is only 210 m. in a straight line. The Kizil Uzain takes up some important affluents and is called Safid Rud from the point where it breaks through the Elburz to the sea, a distance of 7o miles. It drains 25,00o to 30,00o square miles of country. The Herhaz, though not important in length of course, or drainage, also, like the Safid Rud, breaks through the Elburz range from the inner southern scarp to the north. It rises on the slopes of the Kasil Kuh, a peak 12,000 feet in height within the Elburz, and about 25 miles north of Tehran, flows easterly through the Lar plateau, where it is known as the Lar river, and takes up several affluents; turns to the north-east at the foot of Demav end, leaving that mountain to the left, and flows due north past Amol to the Caspian. Its length is about 120 miles. The Gurgan rises on the Armutlu plateau in Khurasan east of Astarabad, and enters the Caspian in 4' north, north-west of Astarabad, after a course of about 200 miles. The Atrek rises a few miles from Kuchan and enters the Caspian at the Bay of Hassan Kuli in 37° 21' north, after a course of about 30o miles. From the sea to the Russian frontier-post of Chat the river forms the frontier between Persia and the Russian Transcaspian region.
The drainage of the rivers which have no outlet to the sea and form inland lakes and swamps (Kavir) may be estimated at 350,000 square miles, including the drainage of Lake Urmia, which is about 20,000 square miles. Fourteen small rivers flow into the lake. During heavy rains and when the snows on the hills melt, thousands of streams flow from all directions into the in numerable depressions of inner Persia, or help to swell the per ennial rivers which have no outlet to the sea. These latter are few in number, and some of them barely suffice for purposes of agricultural irrigation, and in summer dwindle to small rills.