Azerbaijan, officially the Republic of Azerbaijan, is a country in the South Caucasus region of Eurasia at the crossroads of Eastern Europe and Western Asia. It is bounded by the Caspian Sea to the east, Russia to the north, Georgia to the northwest, Armenia to the west and Iran to the south. The exclave of Nakhchivan is bounded by Armenia to the north and east, Iran to the south and west, and has an 11 km (6.8 mi) long border with Turkey in the northwest. The Azerbaijan Democratic Republic proclaimed its independence in 1918 and became the first secular democratic Muslim-majority state. The modern Republic of Azerbaijan proclaimed its independence on 30 August 1991, shortly before the dissolution of the USSR in the same year. Azerbaijan is a unitary semi-presidential republic.