Vietnam lies in the centre of South-East Asia. The closest neighbors of the country are China (in the north), Laos and Kampuchea (in the west). In the east the country is washed by the Pacific Ocean. Vietnam is S-shaped peninsula, with thousands of off-shore islands. The biggest archipelagoes are the Hoang SA (Paracel) and Truong Sa (Spratly). The climate varies greatly from north to south. The north has a cool and dry season from November to April and a hot rainy season from May to October. The weather in the southern part of Vietnam is tropical. The official tourist season in Vietnam is from September to April.