The great mass of the country is steep-sloped with mountains, the ranges fanning out from the towering Hindu Kush (reaching a height of more than 24,000 ft/7,315 m) across the center of the country. There are, however, within the mountain ranges and on their edges, many fertile valleys and plains. In the south, and particularly in the southwest, are great stretches of desert, including the regions of Seistan and Registan. To the north, between the central mountain chains (notably the Selseleh-ye Kuh-e Baba, or Koh-i-Baba, and the Paropamisus) and the Amu Darya (Oxus) River, which marks part of the northern boundary, are the highlands of Badakhshan (with the finest lapis lazuli in the world), Afghan Turkistan, the Amu Darya plain, and the rich valley of Herat on the Hari Rud (Arius) River in the northwest corner of the country (the heart of ancient Ariana). The regions thus vary widely, although most of the land is dry.
The rivers are mostly unnavigable; the longest is the Helmand, which flows generally southwest from the Hindu Kush to the Iranian border. Its water has been used since remote times for irrigation, as have the waters of the Hari Rud and of the Amu Darya. The Kabul River, beside which the capital stands, is particularly famous because it leads to the Khyber Pass and thus S to Pakistan.
Although warfare in Afghanistan during the late 20th cent. caused substantial population displacement, with millions of refugees fleeing into Pakistan and Iran, regional ethnicity remains generally the same as it had been before the unrest. Tajiks live around Herat and in the northeast; Uzbeks live in the north, and nomadic Turkmen live along the Turkmenistan border. In the central mountains are the Hazaras, of Mongolian origin. In the eastern and south central portions Afghans (or Pashtuns), who make up the country's largest ethnic group, are dominant, and Baluchis live in the extreme south. Dari (Afghan Persian), Pashto (Afghan), and various Turkic tongues (mainly Uzbek and Turkmen) are the country's principal languages. A unifying factor is religion, almost all the inhabitants being Muslim; the large majority (about 80%) are Sunni, the minority Shiite. In addition to Kabul, important cities include Kandahar, Herat, and Jalalabad.
The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.