Armenia is a landlocked mountainous country on the crossroads of southern Europe, eastern Europe and western Asia, in the Caucasus region, between the Black Sea and the Caspian Sea. Although it is transcontinental, it is culturally a part of Europe, and the second country in the world to adopt Christianity as its state religion in CE 319. It seeks European Union and NATO membership. It was once part of the USSR. It was the first country in the world to adopt Christianity as its state religion in CE 301.