Vietnam (Vietnamese: Việt Nam, French: Viêt Nam) official name Socialist Republic of Vietnam is a country in Southeast Asia, the second most populous country with a communist regime in the world. It has a total area of 331 690 square kilometers and is bordered north by the People's Republic of China, to the west with Laos and Cambodia, while the east, south and west is bathed by the waters of the Gulf of Tonkin, the South China Sea and the Gulf of Thailand. The country's capital Hanoi is located in the north, but biggest urban center is the city of Ho Chi Minh City, in the south, which until 1976 was called Saigon. According to 2016 estimates the population of Vietnam is 92.513 million inhabitants. Main physiographic feature of Vietnam is the mountains of the Annamite Range, stretching from north to south dominating the interior of the country, and two extensive alluvial delta formed by the Red River (Song Hong) in the north and the Mekong (Song Kuo Long) in the south. The official currency is the đồng (₫) (VND).