ABSTRACT
As a high plateau ringed on all sides by higher mountain ranges, Iran displays a markedly physical unity based on separation from its adjoining regions. To the south and west, the contrast between the massive ranges of the Zagros and the lowlands of Mesopotamia is particularly striking; and on the north, there is an equally abrupt descent from the Elburz ranges to the plains of Russian Turkestan and the basin of the Caspian. Elsewhere, however, the mountain ring of Iran continues with much less interruption into the highlands of eastern Anatolia, and into the more broken massifs of Baluchistan and Afghanistan.
