Most of Iran is highlands: the Central Iranian Plateau and fringing mountains, plus more mountains in the northwest. The only lowlands are a land extension of the Persian Gulf, principally in Khuzestan; the shores of ocean gulfs and straits; the shore of the Caspian Sea(1) and a small piece of the Trans-Caucasian Lowlands north of the Lesser Caucasus mountains. The plateaus rise above 4,000 meters in the center of Sistan-e-Baluchestan Province and drop below 500 meters in that same province's northeast. The plateau includes the Great Salt Desert(2), the Great Sand Desert(3) and several large salt marshes. It is bounded southwest by the Zagros Mountains, rising over 4,000 meters in numerous places; north by the Elburz(4), which reach over 5,000 meters, and by their extension, the Talysh; and northeast by the shorter Kopet Dag mountains. Eastward the plateau continues into neighboring nations. The Talysh meet the Lesser Caucasus mountains in the northwest, rising above 4,000 meters at their junction.
The mouth of the Tigris-Euphrates River system, the Shatt-al-'Arab(5), marks part of the southwestern land border. Lake Urmia(6), nestled in the northwestern mountains, is Asia's sixth or seventh largest lake.
The majority in central and southern Iran speak dialects of Persian (Farsi or Parsi). Most northern Iranians speak Persian or Azeri. In western Iran the three Iranian languages of Persian, Luri and Kurdish together constitute an majority. And in northwestern Iran the majority speak Azeri, a Turkic language.
Almost everyone is a Moslem, and most of the Moslems are Shi'ites.
There are seven cities with a million or more residents. Tehran, the current national capital, has more than 11 million in its metropolitan area in northern Iran, and includes a suburb, Karaj, with more than a million. Three former Iranian capitals and one pilgrimage site in the plateau, Esfahan, Mashdad, Shiraz and Qom, make the list, as does a northwestern city that once was a non-Iranian imperial capital, Tabriz.
Ardabil, Gilan, Mazandaran, Tehran, Qom, Semnan, Markazi and Golestan provinces
Azerbaijan, Gharbi, Azerbaijan Sharqi, Zanjan, Qazvin and Kurdistan provinces
Esfahan, Yazd, Chahar Mahal-e Bakhtiari, Kohgiluyeh-e Boyerahmad, Bushehr, Fars, Khorasan, Kerman, Hormozgan and Sistan-e Baluchestan provinces
Kermanshah, Hamadan, Ilam, Lorestan and Khuzestan provinces
(1) The world's largest lake.
(2) Dasht-e Kavir in transliterated Persian.
(3) Dasht-e Lut in transliterated Persian.
(4) Alborz in strictly transliterated Persian.
(5) Shatt-al-'Arab is transliterated Arabic. It means Arab river mouth.
(6) Oromiyeh in strictly transliterated Persian.