Like Iran, Asia Minor consists essentially of an inner plateau ringed by mountain ranges that for the great part fall away steeply on their outer margins, either to the sea or to lowland areas. Only in the extreme east of Asia Minor are the mountain ranges continued without break; and there the confused highland topography of eastern Anatolia merges on the north-east into the Caucasus, and on the south-east into the Zagros. Structurally, Asia Minor consists of fold systems grouped round two nuclear areas: the Menderes block in the south-west, and the Kirsehir block in the centre (fig. 12.i). Geographical sub-regions may be distin guished as follows:
(1) The Black Sea coastlands extending from the Caucasus of Russia as far west as the region of the Bosphorus.