Azerbaijan, also spelled Azerbaidzhan, officially Azerbaijani Republic, Azerbaijani Azärbayjan Respublikasi, country of eastern Transcaucasia. Occupying an area that fringes the southern flanks of the Caucasus Mountains, it is bounded on the north by Russia, on the east by the Caspian Sea, on the south by Iran, on the west by Armenia, and on the northwest by Georgia. The exclave of Naxçıvan (Nakhichevan) is located southwest of Azerbaijan proper, bounded by Armenia, Iran, and Turkey. Azerbaijan includes within its borders the predominantly Armenian enclave of Nagorno-Karabakh, which from 1988 was the focus of intense conflict between Azerbaijan and Armenia. The capital of Azerbaijan is the ancient city of Baku (Bakı), whose harbour is the best on the Caspian Sea.