Vietnam occupies 331,212 square kilometers on the eastern edge of the Indochina Peninsula. The country extends 1,650 kilometers from its northern border with China to the southern tip of the Cà Mau Peninsula, while its width contracts to 50 kilometers at the narrow waist near Dong Hoi in Quang Binh Province. This S-shaped configuration creates 3,260 kilometers of coastline along the South China Sea, which Vietnamese sources designate as Biển Đông. The maritime boundary includes territorial claims to the Paracel Islands (Hoàng Sa), located approximately 400 kilometers east of Da Nang, and the Spratly Islands (Trường Sa), scattered across 410,000 square kilometers of sea roughly 600 kilometers southeast of Ho Chi Minh City. Both archipelagos remain subjects of overlapping sovereignty claims with China, Taiwan, Malaysia, the Philippines, and Brunei.
The Annamite Range, called Trường Sơn in Vietnamese, forms the dominant structural feature. This mountain chain runs 1,100 kilometers along the western border from China to the Mekong Delta, creating the physical boundary between Vietnam and Laos for much of that distance. The range continues southward into Cambodia. Fansipan, Vietnam's highest point at 3,147 meters, rises within the Hoàng Liên Sơn mountain range in Lào Cai Province, 9 kilometers southwest of Sapa town. The summit sits approximately 380 kilometers northwest of Hanoi. A cable car installed in 2016 runs 6,292.5 meters from Sapa to within 600 meters of the peak, covering the distance in 15 minutes. Before that installation, summit ascents required two to three days of trekking.
Two major river systems create the agricultural foundation. The Red River (Sông Hồng) originates in Yunnan Province, China, enters Vietnam in Lào Cai Province, and flows 510 kilometers southeast to the Tonkin Gulf. The Red River Delta covers 15,000 square kilometers in northern Vietnam, supporting a population density exceeding 1,200 people per square kilometer in some districts. The Mekong River, which Vietnamese call Sông Cửu Long (River of Nine Dragons), enters Vietnam from Cambodia and splits into distributaries that create the Mekong Delta. This southern delta region spans 39,000 square kilometers across 12 provinces and Cần Thơ municipality. The Mekong's Vietnamese distributaries include the Tiền River and Hậu River as the two main branches, which subdivide into the nine channels that give the river its Vietnamese name.
The Red River Delta hosts Hanoi, Vietnam's capital since 1010 when Emperor Lý Thái Tổ moved the capital from Hoa Lư to the Thăng Long citadel site. The delta's alluvial soil reaches depths of 100 meters in some areas. Annual monsoon flooding historically deposited nutrient-rich sediment, though dam construction upstream in China has altered sediment flows since the 1980s. The Hòa Bình Dam on the Đà River, a Red River tributary, began operation in 1994 with a reservoir capacity of 9.45 billion cubic meters. This dam reduced downstream flooding but also decreased sediment deposition that historically maintained delta soil fertility.
The Mekong Delta produces more than half of Vietnam's rice output and accounts for approximately 90 percent of the country's rice exports. The delta's elevation ranges from zero to two meters above sea level across most of its extent. Tidal influence reaches 60 kilometers inland during the dry season. The delta experiences two distinct hydrological seasons: the flood season from August to November when Mekong discharge can exceed 40,000 cubic meters per second at Tân Châu, and the dry season from December to April when saltwater intrusion penetrates up to 60 kilometers inland along major distributaries. The Vietnamese government completed the Ô Môn sluice gate in 2001 near Cần Thơ, controlling saltwater intrusion and freshwater drainage across 34,000 hectares.
The Central Highlands (Tây Nguyên) form a plateau region spanning five provinces: Kon Tum, Gia Lai, Đắk Lắk, Đắk Nông, and Lâm Đồng. This region covers 54,474 square kilometers at elevations between 500 and 1,500 meters. The basalt soil, formed from volcanic activity that ceased approximately 2.6 million years ago, creates conditions for coffee cultivation. Vietnam became the world's second-largest coffee exporter in 1999 and the largest in 2000, a position it has maintained in most subsequent years. The Central Highlands now contain approximately 500,000 hectares of coffee plantations, predominantly Robusta variety. Đắk Lắk Province alone accounts for roughly 30 percent of Vietnam's total coffee production.
Phú Quốc Island, Vietnam's largest island at 574 square kilometers, lies in the Gulf of Thailand 45 kilometers west of Hà Tiên on the mainland. The island reaches 603 meters elevation at Mount Heaven (Chúa Mountain). Phú Quốc became a province-level municipality separate from Kiên Giang Province in 2020. Cát Bà Island, covering 285 square kilometers in Hải Phòng municipality, forms the largest island in the Cát Bà Archipelago of 367 islands in Hạ Long Bay's western section. The Côn Đảo Islands consist of 16 islands located 180 kilometers southeast of Vũng Tàu, with the main island (Côn Sơn) covering 51.5 square kilometers.
Ha Long Bay contains approximately 1,600 limestone islands and islets across 1,553 square kilometers in Quảng Ninh Province. UNESCO inscribed the core zone of 434 square kilometers as a World Heritage Site in 1994, extending the inscription to 1,969 square kilometers in 2000. The limestone karsts rise directly from sea level, reaching maximum heights near 200 meters. Geologists date the limestone formation to the Carboniferous and Permian periods 340 to 250 million years ago. The karst landscape developed through erosion over the past 20 million years. Sea level rise approximately 8,000 years ago flooded the eroded landscape, creating the current bay configuration.
Phong Nha-Kẻ Bàng National Park in Quảng Bình Province protects 857.54 square kilometers of karst landscape containing over 300 documented caves. UNESCO designated the park as a World Heritage Site in 2003, recognizing the oldest karst formation in Asia at 400 million years. Sơn Đoòng Cave, discovered in 1991 by local resident Hồ Khanh and first explored by British Cave Research Association cavers in 2009, measures 5 kilometers in surveyed length with sections reaching 200 meters in height and 150 meters in width. The largest chamber volume exceeds 38.5 million cubic meters. Paradise Cave (Thiên Đường Cave), located 25 kilometers northwest of Phong Nha Cave, extends 31.4 kilometers in surveyed passages, making it one of the longest dry caves in the world. The tourist route opened in 2010 covers one kilometer of wooden walkways.
The Tràng An Landscape Complex in Ninh Bình Province encompasses 2,168 hectares of limestone karst peaks intersected by waterways. UNESCO inscribed Tràng An as a mixed natural-cultural World Heritage Site in 2014. The karst towers rise 200 meters above sea level. The complex contains 48 documented caves formed by river erosion cutting through limestone. Archaeological excavations in caves at Tràng An recovered stone tools and evidence of human occupation spanning from 30,000 years ago through various prehistoric periods. The nearby Tam Cốc area features three caves through which the Ngô Đồng River flows: Hang Ca (127 meters long), Hang Hai (60 meters), and Hang Ba (40 meters).
Cúc Phương National Park, established in 1962 as Vietnam's first national park, protects 22,200 hectares of lowland karst forest in Ninh Bình Province, 120 kilometers southwest of Hanoi. The park's elevation ranges from 150 to 656 meters at Mây Bạc peak. Botanical surveys have documented 2,234 vascular plant species within the park. The park contains a 1,000-year-old Parashorea chinensis tree measuring 45 meters in height. Cát Tiên National Park in the southern region covers 71,920 hectares across three provinces (Đồng Nai, Lâm Đồng, Bình Phước). The park protects lowland tropical rainforest at elevations between 100 and 600 meters. Wildlife surveys have recorded 105 mammal species, including a population of Javan rhinoceros that went extinct in Vietnam in 2010 when the last individual was found dead from poaching.
The Central Highlands topography creates distinct climate zones. Đà Lạt, located at 1,500 meters elevation in Lâm Đồng Province, experiences average temperatures between 15 and 24 degrees Celsius year-round. The city receives approximately 1,775 millimeters of annual rainfall, concentrated between May and October. This elevation-moderated climate enabled French colonists to establish temperate crop cultivation in the 1920s and 1930s. Đà Lạt now produces approximately 30,000 tons of fresh vegetables annually, along with flowers shipped to markets throughout Vietnam. Lang Biang Mountain, 12 kilometers north of Đà Lạt, reaches 2,167 meters across two peaks (Radar Mountain and K'lang Peak).
Vietnam's monsoon patterns create regional climate variation. Northern Vietnam experiences four distinct seasons with a cool dry winter from November to April when northeast monsoons bring continental air masses from China. Hanoi's January average temperature is 16.4 degrees Celsius, with recorded minimums near 3 degrees Celsius. The southwest monsoon from May to October brings heavy rainfall. Hanoi receives an average 1,676 millimeters of annual precipitation, with 80 percent falling between May and October. Southern Vietnam experiences two seasons: wet from May to November and dry from December to April. Ho Chi Minh City receives approximately 1,931 millimeters annually, with monthly temperatures varying only between 25 and 28 degrees Celsius average.
Central Vietnam receives peak rainfall from September to December when the retreating southwest monsoon and early northeast monsoon converge. This pattern creates annual flooding in provinces from Quảng Bình to Bình Định. Huế city averages 2,862 millimeters of annual rainfall, making it Vietnam's wettest major city. October and November together account for approximately 1,400 millimeters. Typhoons cross the Vietnamese coast an average of 4 to 6 times annually, primarily between July and November. Typhoon Linda in November 1997 killed an estimated 3,000 people, predominantly fishermen at sea. Typhoon Damrey in November 2017 made landfall in Khánh Hòa Province with sustained winds of 165 kilometers per hour, killing 106 people.
The Tonkin Gulf coastline from Móng Cái to Thanh Hóa Province features rocky headlands and pocket beaches. The coastal plain widens south of Thanh Hóa, creating the Red River Delta lowlands. From Quảng Bình to Bình Thuận provinces, the Annamite Range approaches within 40 to 80 kilometers of the coast. This creates a narrow coastal plain punctuated by river valleys. Cù Lao Chàm, a group of eight islands 18 kilometers east of Hội An, covers 15 square kilometers. UNESCO designated Cù Lao Chàm as part of the Cù Lao Chàm-Hội An Biosphere Reserve in 2009. The islands protect 165 documented coral species.
The southeastern coastal region from Bình Thuận to Bà Rịa-Vũng Tàu features extensive sandy beaches. Mũi Né, located 22 kilometers northeast of Phan Thiết city, contains red and white sand dunes extending several kilometers inland. The white dunes reach heights of 50 meters. These formations result from beach sand transported inland by monsoon winds. The Bach Ho offshore oil field, located 145 kilometers southeast of Vũng Tàu, began production in 1986 as Vietnam's first offshore petroleum development. Current production from the Nam Con Son Basin and other fields totals approximately 200,000 barrels per day.
The Mekong Delta coastline features mangrove forests and mudflats. The Cà Mau Peninsula forms Vietnam's southernmost point at 8°35'N latitude. Mũi Cà Mau National Park protects 41,862 hectares of coastal mangrove ecosystems. The park contains the narrowest mangrove forest strip at 2 to 3 kilometers wide and the widest at 20 kilometers. Tràm Chim National Park in Đồng Tháp Province encompasses 7,588 hectares of seasonally flooded grassland and melaleuca forest. The park provides habitat for the critically endangered eastern sarus crane (Antigone antigone sharpii), with a population fluctuating between 100 and 1,000 individuals depending on water levels.
Hòn Tre Island, located 3 kilometers east of Nha Trang, covers 36 square kilometers. A 3,320-meter cable car connects the island to the mainland, installed in 2007. The island rises to 500 meters elevation. Vinpearl, a resort and amusement park complex, occupies approximately 200,000 square meters of the northern shore. The Con Dao Archipelago's main island (Côn Sơn) rises to 577 meters at Mount Thanh Giá. Con Dao National Park protects 20,000 hectares of land and sea area. The waters surrounding Con Dao support coral reefs covering approximately 1,377 hectares, with documented coral coverage of 30 to 50 percent in protected zones.
The Central Highlands' basalt plateaus experience seasonal transformation. During the wet season from May to October, approximately 1,800 to 2,500 millimeters of rain falls on the highlands. This creates conditions for rainforest vegetation at elevations above 800 meters. The dry season from November to April brings monthly rainfall below 50 millimeters. Forest clearing for agriculture since the 1980s removed approximately 270,000 hectares of highland forest. Yok Đôn National Park in Đắk Lắk Province protects 115,545 hectares of dry deciduous dipterocarp forest, the largest remaining block of this ecosystem in mainland Southeast Asia. Wildlife surveys in 2010 documented 63 mammal species, including a small population of Asian elephants numbering approximately 60 individuals.
Ba Bể National Park in Bắc Kạn Province centers on Ba Bể Lake, Vietnam's largest natural lake at 650 hectares surface area. The lake occupies a tectonic depression at 145 meters elevation, with maximum depth reaching 35 meters. Three linked lakes (Pé Lầm, Pé Lù, and Pé Lèng) form the Ba Bể system. The Năng River flows through the lakes, entering through Puổng Cave (300 meters long) and exiting through Hua Mạ Cave. The national park protects 10,048 hectares of limestone karst forest surrounding the lake. Botanical surveys have recorded 1,268 vascular plant species within the park boundaries.
Bạch Mã National Park in Thừa Thiên-Huế Province protects 37,487 hectares across an elevation range from sea level to 1,444 meters at Bạch Mã Peak. The park receives 3,000 to 8,000 millimeters of annual rainfall depending on elevation, making it one of Vietnam's wettest locations. French colonial authorities established a hill station on Bạch Mã mountain in 1932, constructing approximately 139 villas at elevations between 1,250 and 1,444 meters. Most structures were abandoned and destroyed during the war years. A 19-kilometer road built in 1937 connects the summit to the park entrance.