Iran is one of the major constituent regions of the ancient world, located in southwest Asia, between the Indus and the Tigris rivers. It is bounded to the north by the Central Asian steppes, the Caspian Sea, and the mountains of Caucasus; to the west by the Anatolian Plateau and the plains of Mesopotamia; to the south by the Persian Gulf and the Sea of Oman; and to the east by present-day countries of Pakistan and Afghanistan. Iran is estimated to have over 300,000 archaeological sites, dating from the Old Stone Age to medieval times. These sites range from prehistoric caves, shelters, and campsites to highly complex monuments and cities. The archaeological exploration of the country began as early as the seventeenth century and led to the formation of archaeological institutions and the creation of Iranian archaeology disciplines and curricula in Iran, Europe, and North America.
And see AWOL's Roundup of Resources on Ancient Geography