Myanmar spans 676,578 square kilometers, making it the largest country in mainland Southeast Asia and the 40th largest nation globally. The country extends roughly 2,090 kilometers from north to south and 925 kilometers at its widest point from east to west. Myanmar shares land borders with five nations: Bangladesh and India to the west, China to the north and northeast, Laos to the east, and Thailand to the southeast. The country possesses 2,832 kilometers of coastline along the Bay of Bengal to the west and the Andaman Sea to the south.
The Irrawaddy River forms Myanmar's primary geographical axis, flowing 2,210 kilometers from its source in the confluence of the Mali and N'mai rivers in Kachin State southward through the country's center before emptying into the Andaman Sea. The river's drainage basin covers approximately 411,000 square kilometers, roughly 60 percent of Myanmar's total land area. The Irrawaddy remains navigable for shallow-draft vessels as far north as Myitkyina, a distance of 1,450 kilometers from the sea. At Mandalay, during the rainy season, the river reaches widths exceeding 3 kilometers. The Irrawaddy Delta, where the river splits into multiple channels before reaching the sea, covers approximately 30,000 square kilometers of low-lying terrain crisscrossed by distributaries, tidal creeks, and brackish water channels.
The Chindwin River, the Irrawaddy's largest tributary, flows 1,158 kilometers from its source in the Patkai Range before joining the Irrawaddy near Pakokku in central Myanmar. The Salween River, known as the Thanlwin River within Myanmar, runs 2,815 kilometers total, with its final 1,200 kilometers flowing through eastern Myanmar. The Salween enters Myanmar from China in Shan State and forms part of the Myanmar-Thailand border before emptying into the Gulf of Martaban. The Sittaung River flows 563 kilometers through central Myanmar, running parallel to and east of the Irrawaddy before reaching the Gulf of Martaban near Mawlamyine. Unlike the Irrawaddy, the Sittaung's course through the Bago Mountains makes navigation difficult.
Hkakabo Razi, located in Kachin State near the borders with China and India, stands at 5,881 meters above sea level, making it Myanmar's highest peak and the highest mountain in Southeast Asia. The mountain sits within the Hkakabo Razi National Park, established in 1996 and covering 3,812 square kilometers. The first confirmed successful ascent occurred in 1996 by a Japanese expedition led by Takashi Ozaki. A 2014 measurement using GPS and laser technology by a joint American-Myanmar expedition led by Giles Dodson and Hilaing Khaung confirmed the 5,881-meter elevation, though some earlier sources cited 5,967 meters. The mountain remains extremely difficult to access due to dense jungle, steep terrain, and political restrictions in the northern border region.
The Shan Plateau dominates eastern Myanmar, covering approximately 155,000 square kilometers at an average elevation between 900 and 1,200 meters above sea level. The plateau extends across most of Shan State, Myanmar's largest administrative division at 155,801 square kilometers. The plateau's western edge rises abruptly from the central lowlands, creating a dramatic escarpment visible from Mandalay and other central Myanmar cities. The plateau surface itself consists of rolling hills, river valleys, and occasional mountain ranges reaching 2,000 to 2,500 meters. The Thazi Gap, located at approximately 22 degrees north latitude, provides the primary route from central Myanmar up onto the plateau, used by the Yangon-Mandalay-Lashio railway and highway.
The Arakan Mountains, also called the Rakhine Mountains, run approximately 950 kilometers along Myanmar's western edge, forming a natural barrier between the coastal strip and the central lowlands. The range begins near the Indian border in the north and extends southward into the Tanintharyi Region. Peaks in the northern section reach above 3,000 meters, with Mount Victoria, also known as Natmataung or Khaw nu Soum, standing at 3,094 meters as the highest point. Natmataung National Park, established in 1994, covers 279 square kilometers around Mount Victoria. The Arakan Mountains create a rain shadow effect, with western slopes receiving monsoon rains exceeding 5,000 millimeters annually while eastern slopes receive less than 1,000 millimeters in some areas.
The Bago Mountains run north to south between the Irrawaddy and Sittaung rivers in south-central Myanmar, extending approximately 435 kilometers with a maximum width of about 95 kilometers. Peak elevations range from 600 to 1,100 meters, with the highest point reaching approximately 1,518 meters. The range historically limited east-west communication between the Irrawaddy Delta and the Sittaung River valley. The Bago Mountains contain mixed deciduous forests and historically served as a major source of teak timber.
The Tanintharyi Range forms the mountainous spine of southern Myanmar, running approximately 700 kilometers along the narrow southern peninsula between the Andaman Sea and the Thailand border. The range continues south into Thailand as the Tenasserim Hills. Elevations generally range from 1,000 to 1,500 meters, with some peaks exceeding 2,000 meters. The Tanintharyi Range receives heavy monsoon rainfall exceeding 4,500 millimeters annually in some locations, supporting dense tropical rainforest. The narrow coastal plain between the mountains and the Andaman Sea varies from just a few kilometers wide to approximately 30 kilometers at its widest points.
Myanmar's coastline extends 2,832 kilometers from the mouth of the Naf River on the Bangladesh border south to the mouth of the Pakchan River on the Thailand border. The coast divides into distinct sections: the Rakhine coast along the Bay of Bengal from the Bangladesh border to the Irrawaddy Delta, the delta itself, and the Tanintharyi coast along the Andaman Sea. The Rakhine coast features the port city of Sittwe and several offshore islands. The delta coastline consists of low-lying mudflats, mangrove forests, and constantly shifting channels. The Tanintharyi coast remains relatively undeveloped compared to neighboring Thailand's Andaman coast.
The Mergui Archipelago, also called the Myeik Archipelago, consists of more than 800 islands extending approximately 400 kilometers along the Tanintharyi coast from roughly 10 degrees to 13 degrees north latitude. Most islands remain uninhabited or support only small fishing communities. The larger islands include Lampi Island, covering 188 square kilometers, Kyun Phi Lar, Sullivan Island, Bentinck Island, and Malcolm Island. Lampi Island Marine National Park, established in 1996, covers 213 square kilometers including the island and surrounding waters. The archipelago's isolation preserved extensive coral reefs and mangrove forests, though commercial fishing pressure has increased in recent decades. The indigenous Moken people, sea nomads also known as Salon, traditionally inhabited many islands, though their traditional lifestyle faces pressure from development and settlement policies.
Inle Lake sits at 880 meters elevation in the Shan Hills, extending approximately 22 kilometers north to south with an average width of 10 kilometers and a surface area of 116 square kilometers during the dry season. Water depth averages 2 to 3 meters, with maximum depths reaching 3.6 meters in some areas. The lake expands during the monsoon season, sometimes exceeding 160 square kilometers. Inle Lake's watershed covers approximately 2,950 square kilometers, with more than 30 feeder streams draining from surrounding mountains. The lake drains through a single outlet at its southern end, flowing into the Bilu Creek which eventually joins the Salween River. The lake supports approximately 70,000 people living in villages built on stilts over the water or along the shores. Inle Lake became a UNESCO Biosphere Reserve in 2015, though agricultural runoff, sedimentation, and water hyacinth invasion continue degrading water quality. The lake's surface area has reportedly decreased due to sedimentation from deforestation in the watershed, with some estimates suggesting the lake has lost more than 30 percent of its area since the 1930s.