The three regions
It is conventional to divide Vietnam into three distinct regions, corresponding to the divisions adopted by the French and the Vietnamese vision of their own country: the north or Bac-bô (Tonkin), the center or Trung-bô (Annam) and the south or Nam-bô (Cochinchina). Nevertheless, from a geographical point of view, these three regions do not present a coherent picture of the country's diversity.
The relief of North Vietnam
Vietnam is essentially a country of hills, mountains and high plateaus. There are three main mountainous zones in Vietnam: the northwestern zone, on the right bank of the Red River; the north/northeastern zone, on the left bank of the Red River; and the Truong Son range, which separates Vietnam from Laos and part of Cambodia.
The north-west zone. With mountain ranges of varying heights and plateaus running parallel to each other in a north-west-south-east direction, the area to the north-west of the Red River valley is the most rugged. The Hoang Liên Son range, the eastern extension of the Himalayan complex, is jagged with steep, almost vertical peaks that are the highest in the country. In Lao Cai province, to the south-west of the high-altitude resort of Sapa, Fan Si Pan, the highest peak in Indochina, rises to 3,147.3m. Its rugged beauty has unfortunately been disfigured by the construction of a cable car.
The north/northeast zone. North of the Red River valley, in Ha Giang province, several mountain ranges have peaks rising above 2,000 m (Tây Côn Linh, 2,431 m; Kiêu Liêu Ti, 2,402 m). The Chay River massif and the Dong Van karst plateau (between 1,400 and 1,600 m altitude), rich in spectacular scenery and populated by ethnic minorities, are particularly recommended destinations for hiking enthusiasts. Further east, up to the coast of Quang Ninh province, a region of low mountains (the majority no higher than 1,000 m) and hills ("moyenne région"). A multitude of valleys lead to China. Since ancient times, the region has always been the scene of major traffic flows, the crossing point for invasions, migrations and trade.
The Truong Son Cordillera. Formerly known as the "Annamite Cordillera", it is often referred to as the "backbone" of the country. The term "cordillera" is simplistic, however, since it generically encompasses a succession of ranges and plateaus that do not all belong to the same geological unit. The Truong Son Cordillera stretches 1,200 km from north to south, from Thanh Hoa province to Lâm Dông province. It separates Vietnam from Laos. Several passes allow passage between the two countries. In Quang Binh province, north-west of Dông Hoi, the Mu Gia pass (418 m) was the starting point of the famous Hô Chi Minh trail.
South of the Hai Van Pass (or "Cloud Pass", north of the city of Da Nang), in the provinces of Kontum, Gia Lai, Dak Lak, Dak Nông and Lâm Dông, is a massif with a different geological history, characterized by high plateaus once covered by forest and savannah, the cradle of the indigenous peoples. Thanks to the richness of its red basalt soils, this area of high plateau (in Vietnamese, Tây Nguyên) is now specialized in large-scale agricultural production: coffee, tea, pepper, cashew nuts, rubber..
Karst relief. Karst formations are a distinctive feature of the Vietnamese landscape. The spectacular seascape of Along Bay, made up of hundreds of limestone islands and islets jagged by wind, sea spray and the passage of centuries, eroded by the obstinacy of ocean currents and storms, and carved into labyrinthine caves, is inscribed on UNESCO's World Heritage List. Karst was originally a local term for the limestone plateaus of the north-western Balkans. By extension, it has come to apply to any limestone region with related characteristics. Several factors combine to explain the genesis and evolution of karsts, including tectonic movements, the nature of the rock, vegetation and climate. In Vietnam, karst massifs are concentrated mainly in the north, as an extension of the world's largest karst region, that of south-eastern China. The coastal zone, with Along Bay and Cat Ba Island, is well known, but other places are also remarkable, including the Dong Van plateau, in the far north of the country, already mentioned; the Cao Bang massif, in the northeast, where you can visit the Ban Giôc waterfalls; the "terrestrial Halong Bay" in Ninh Binh province, south of Hanoi.
These natural wonders have been the setting for blockbuster films such as Indochine (by Régis Wargnier, 1992), filmed in Halong Bay and Ninh Binh province, and more recently, Kong: Skull Island (J. Vogt-Roberts, 2017), filmed in Halong Bay and Ninh Binh province. In addition to their scenic appeal, the karst massifs are also ideal for sporting activities, including rock climbing, which is particularly popular on Cat Ba Island.
The rivers of North Vietnam
Between the mountains and the sea, two deltaic plains - the Red River delta to the north, the Mekong delta to the south - are linked by a narrow coastal strip. The plains occupy just one-fifth of the total surface area, but are home to four-fifths of the population. Life on the deltaic plains depends largely on flooding. During the high-water season, rivers carry 80% of their total annual flow, compared with 20% during low-water periods. River banks are submerged, sometimes up to +6 or +12 m (+12.3 m in Hanoi in 1945, while some of the city's streets are only +4 m high), and their course is changeable and uncertain over part of their length. Water plays an essential role in the Vietnamese imagination. For the delta farmer, taming the land means first and foremost mastering the water. In reference to this osmosis, to speak of their "country", the Vietnamese use the term dât-nuoc, which translates as land-water.
The Red River delta. To the north, the Red River delta(BacBô, in Vietnamese), an ancient gulf filled by the alluvial deposits of the Thai Binh river(sông), but above all by the Red River. The 1,200 km-long Red River rises in the highlands of China's Yunnan province. It is at Lao Cai (1,180 km from the sea and 800 m above sea level) that the Red River enters Vietnam. Up to Yên Bai, the valley remains straight and deep. The river swells downstream from its tributaries, the Rivière Noire(sông Da) and the Rivière Claire (sông Lo), which also descend from southern China. It enters the delta near the town of Viêt Tri. It then meanders lazily towards its many mouths. During the high-water period (June to October), due to the dual action of snowmelt (upstream, in the Chinese part) and monsoon rains, the Red River's floods can be very high, occurring in rapid, irregular succession. This has always necessitated the construction of a system of dykes, which over thousands of years have shaped the delta's landscape. In 1108, under the Ly dynasty, annals record the first large-scale construction of dykes, but the Red River is thought to have been dammed as early as 43 CE. The Red River delta was the earliest concentration point of the Viêt, mentioned as early as the 3rd century BC, and the center of a civilization based on irrigated rice cultivation and on cultural practices and customs closely linked to water, which are still deeply imprinted on today's villages.
From the Red River delta to the Mekong delta, a string of small coastal plains stretches out, which, south of the Ngang pass (Hoanh Son gateway, known as the "Annam gateway", between the provinces of Ha Tinh and Quang Binh), are divided by the foothills of the Truong Son mountain range, which juts out to the coast.
The coastline
Vietnam's coastline stretches over 3,000 km and offers a wide variety of landscapes. To the north lies the prestigious Halong Bay.
From the Gulf of Bac Bô (or Gulf of Tonkin) in the north to the Gulf of Thailand in the south, Vietnam has more than 3,000 offshore islands and archipelagos. Among those accessible and open to tourism are, in northern Vietnam, the island of Cat Ba (the largest island in Halong Bay) and the Cu Lao Cham archipelago (Quang Nam province).
Vietnam has a maritime domain three times the size of its land territory. The South China Sea (Biên Dông [East Sea] in Vietnamese) is a semi-enclosed sea that communicates to the north with the Pacific Ocean, and to the south-west, via the Strait of Malacca, with the Indian Ocean. These busy waters - through which a third of the world's maritime traffic passes - are also rich in fish and hydrocarbons. This poorly demarcated maritime space is the subject of territorial disputes between riparian states, but tensions are now aggravated by China's increasingly aggressive policies to impose its sovereignty. Its maritime openness therefore gives Vietnam an important place in world geopolitics, particularly in an international context marked by the maritimization of issues and the shift of the strategic center of gravity towards the Pacific Ocean.
