Red River (Asia) in the context of Möng Mao

The Red River Delta or Hong River Delta (Vietnamese: Đồng bằng sông Hồng) is the flat low-lying plain formed by the Red River and its distributaries merging with the Thái Bình River in Northern Vietnam. Hồng (紅) is a Sino-Vietnamese word for "red" or "crimson". The delta has the smallest area but highest population and population density of all regions in Vietnam. The region, measuring some 15,000 square kilometres (6,000 sq mi) is well protected by a network of dikes. It is an agriculturally rich and densely populated area. Most of the land is devoted to rice cultivation.

Eight provinces, together with two municipalities (the capital Hanoi, and the port of Haiphong) form the delta. It had a population of almost 23 million in 2019.

The People's Republic of China (PRC) shares land borders with 14 countries (tied with Russia for the most in the world): North Korea, Russia, Mongolia, Kazakhstan, Kyrgyzstan, Tajikistan, Afghanistan, Pakistan, India, Nepal, Bhutan, Myanmar, Laos, and Vietnam, and with two Special administrative regions of China, Hong Kong and Macao. The land borders, counterclockwise from northeast to southwest, are the China–North Korea border, the eastern segment of the China–Russia border, the China–Mongolia border, the western segment of the China–Russia border, the China–Kazakhstan border, the China–Kyrgyzstan border, the China–Tajikistan border, the China–Afghanistan border, the China–Pakistan border, the western segment of the China–India border (the most contested of the Sino-Indian border dispute), the China–Nepal border, the central segment of the China–India border (Sikkim), the China–Bhutan border, the eastern segment of the China–India border, the China–Myanmar border, the China–Laos border, the China–Vietnam border, a 3-kilometre (1.9 mi) internal border with Macau, a Portuguese territory until 1999, and a 30-kilometre (19 mi) internal border with the special administrative region of Hong Kong, which was a British dependency before 1997.

To the west, China has maritime borders with North Korea, Japan and contested limits with Taiwan and other countries in the South China Sea, among other territorial disputes.

Hanoi (/hæˈnɔɪ/ han-OY; Vietnamese: Hà Nội [hàː nôjˀ] ) is the capital and second-most populous city of Vietnam. The name "Hanoi" translates to "inside the river" (Hanoi is bordered by the Red and Black Rivers). The city encompasses an area of 3,358.6 km (1,296.8 sq mi), and as of 2025 has a population of 8,807,523. Hanoi had the second-highest gross regional domestic product of all Vietnamese provinces and municipalities at US$48 billion in 2023, behind only Ho Chi Minh City.

In the third century BCE, the Cổ Loa Capital Citadel of Âu Lạc was constructed in what is now Hanoi. Âu Lạc then fell under Chinese rule for a thousand years. In 1010, under the Lý dynasty, Vietnamese emperor Lý Thái Tổ established the capital of the imperial Vietnamese nation Đại Việt in modern-day central Hanoi, naming the city Thăng Long [tʰɐŋ loŋ], 'ascending dragon'). In 1428, King Lê Lợi renamed the city to Đông Kinh [ɗoŋ kīŋ̟], 'eastern capital'), and it remained so until 1789. The Nguyễn dynasty in 1802 moved the national capital to Huế and the city was renamed Hanoi in 1831. It served as the capital of French Indochina from 1902 to 1945 and French protectorate of Tonkin from 1883 to 1949. After the August Revolution and the fall of the Nguyễn dynasty, the Democratic Republic of Vietnam (DRV) designated Hanoi as the capital of the newly independent country. From 1949 to 1954, it was part of the State of Vietnam. It was again part of the DRV ruling North Vietnam from 1954 to 1976. In 1976, it became the capital of the unified Socialist Republic of Vietnam. In 2008, Hà Tây Province and two other rural districts were annexed into Hanoi, almost tripling Hanoi's area.

The Red River Fault or Song Hong Fault (Vietnamese: Đới Đứt Gãy Sông Hồng) is a major fault in Yunnan, China and Vietnam which accommodates continental China's (Yangtze plate) southward movement. It is coupled with that of the Sagaing Fault in Burma, which accommodates the Indian plate's northward movement, with the land (Indochina) in between faulted and twisted clockwise. It was responsible for the 1970 Tonghai earthquake.

It is named after the Red River which runs through the valley eroded along the fault trace.

The Thái Bình river system is one of the two major river systems in the Red River Delta, Vietnam; the other one is the Red River system. Both split from the Red River in the Hưng Yên province. The system consists of 8 rivers flowing in northern Vietnam. This system joining with Red River system creates the Red River Delta.

The part of it between Hưng Yên and the sea, in combination with the part of the Red River from Hanoi to Hưng Yên, was called the River of Tonkin by historical Dutch and English texts.

The Red River system is a network of rivers or delta system surrounding the main river - Red River in North Vietnam. These branches of the system contribute to or receive water from Red River. Red River system, joining with the Thái Bình river system in the northeast, creates the Red River Delta - the second largest delta in Vietnam,because of the close relation between Red River system and Thái Bình river system, the two system are known as the common name Red and Thai Binh rivers system. Alluvium of the Red River system creates the central and south Red River Delta. Two banks of the rivers are protected by a great dyke system.

The area has a high population density, with some 20% of Vietnam's residents living in the delta. The network of the Red River system has been used for much of human history as a route for the movement of people and for trade, including as a maritime corridor within the historic Chinese Southwest silk road.

The Bạch Đằng River (Vietnamese: Sông Bạch Đằng, IPA: [ʂoŋ ɓâjk̟ ɗɐ̀ŋ]), also called Bạch Đằng Giang (from 白藤江, IPA: [ɓâjk̟ ɗɐ̀ŋ ʑaːŋ]), the White Wisteria River, is a river in northern Vietnam, located near Hạ Long Bay. It flows through Yên Hưng District of Quảng Ninh province and the district Thủy Nguyên of Haiphong.

It is the best river way to access Hanoi from the south of China, through the Nam Triệu Mouth, the Kinh Thầy River, the Đuống River, and then the Red River to Hanoi.

Tuyên Quang (Vietnamese: [tʷiə̄n kʷāːŋ]) is a province of Vietnam, located in the northeastern part of the country to the northwest of Hanoi, at the centre of Lô River valley, a tributary of the Red River. Its capital is Minh Xuân Ward. The province had a population of 1,865,270 in 2025, with a density of 137 persons per km over a total land area of 13,795.50 square kilometres (5,326.47 sq mi).

Tuyên Quang Province is bordered to the northeast by Cao Bằng Province, to the east by Thái Nguyên Province, to the south by Phú Thọ Province, to the west by Lào Cai Province, and to the north by Wenshan Zhuang and Miao Autonomous Prefecture, Yunnan Province and Baise City, Guangxi Zhuang Autonomous Region of China.

Phú Thọ is a province in northern Vietnam. Its administration center Việt Trì ward is located 80 kilometres (50 mi) from Hanoi and 50 kilometres (31 mi) from Nội Bài International Airport. The province covers an area of 9,631.38 km (3,718.70 sq mi) and, as of 2025, it had a population of 4,022,638.

The history of Phú Thọ is linked to the 18 dynasties of Hùng kings who were credited with building the nation of Văn Lang. Because of its strategic location, the province is known as the "West Gate of Hanoi". It is located at the confluence of two large rivers: the Red River and the Da River, and in a transitional area between the Red River Delta the country's northern mountainous provinces. The Xuân Sơn National Park, established in February 2002, is located in the province about 80 kilometres (50 mi) from Việt Trì. The park covers an area of 15,048 hectares (37,180 acres), with over 11,000 hectares (27,000 acres) of natural forest and 1,396 hectares (3,450 acres) of limestone-mountain forests. Phú Thọ is one of the poorest areas of Vietnam and the poorest households earn below US$6 per person per month. Tea is important to the economy of the province. The Hung Kings temple complex, located on Nghĩa Lĩnh mountain in Việt Trì, is a complex of majestic architecture enclosing Hạ Temple (built in the 15th century), Thiện Quang pagoda, Giếng, Trung and Thuong temples, and King Hung's tomb.