Vietnam is located in the eastern part of the Indochina Peninsula, stretching along the South China Sea, from which in the northern part, between the coast of Vietnam and the Chinese island of Hainan, The Gulf of Tonkin stands out. The country includes offshore islands: Phu Quoc in the Gulf of Thailand on the border with Cambodia. Con Dao south of the Mekong Delta and the Fai Tsi Long archipelago between the Chinese border and the Red River Delta, with the largest island of Cat Ba.
Mountains and plateaus
Mountain and upland areas occupy 3/4 country area, the rest falls on extensive, alluvial deltas of the Red River in the north and the Mekong in the south, and a strip of coastal lowlands. The area between the deltas, with an extension of approx 1100 km, occupy, separated from the sea by a narrow strip of alluvial plains, The Annamite Mountains (Truong Son), exceeding in the middle part 2500 m n.p.m. To the south and west they turn into crystalline plateaus: Gia Lai, Dac Lac, Ma. In the Cong Tum plateau there are cones of extinct volcanoes and basalt covers cut by river valleys. The northern part of the country is occupied by the Viet Bac highlands. A characteristic feature of these areas is the presence of humas, that is, limestone outliers with a rounded shape. Humami are also the numerous rocky islands in the Ha Long Bay.
Vietnam is in the zone of monsoon climates – in the tropical north, and in the south of the equatorial. They are characterized by the presence of two clearly marked seasons: hot and humid in summer (from May to October) and dry and cooler in winter (from November to April). This is related to a change in the wind direction. Blowing in summer from the ocean in the south and southwest, it brings moisture and high rainfall (2000 mm in Hoshimin and 1650 mm in Hanoi), while in winter it is dry, continental, from the North and Northeast. In northern Vietnam, there is a severe drizzle at the end of the dry season, increasing air humidity to 91%. In summer and autumn, the coasts are haunted by devastating typhoons that form at the interface between warm and cool air masses.