Vietnam is a long, narrow nation shaped like the letter s. It is in Southeast Asia on the eastern edge of the peninsula known as Indochina. Its neighbors include China to the north and Laos and Cambodia to the west. The South China Sea lies to the east and south. The mountains of the Annam Cordillera rise over most of the western side of Vietnam, while a thousand-mile (1,600-kilometer) coastline dominates the east.