Armenia is a landlocked mountainous country between the Black Sea and the Caspian Sea, in the southern Caucasus. It shares borders with Turkey to the west, Georgia to the north, Azerbaijan to the east, and Iran and the Nakhchivan exclave of Azerbaijan to the south. Its total area is 29 743 km2. A former republic of the Soviet Union, Armenia is a unitary, multi-party, democratic nation state with an ancient cultural heritage. Armenia prides itself on being the first nation formally to adopt Christianity (in the early 4th century).