Malaysia is a Southeast Asian country of 330,803 km² split into two parts by the South China Sea: Peninsular Malaysia, the southern half of the Malay Peninsula below Thailand, with about 40 percent of the land, and East Malaysia, the states of Sabah and Sarawak on northern Borneo, with the other 60 percent. Both halves share one basic shape, coastal plains rising to forested hills and mountains, with the Titiwangsa Range running down the peninsula's spine and the Crocker Range dividing Sabah. The highest point is Mount Kinabalu in Sabah at 4,095 m, the longest river is the Rajang in Sarawak at about 565 km, and the longest on the peninsula is the Pahang at 459 km. People are distributed very unevenly across that land: the 2020 census counted 32.4 million people, and about four in five live on the smaller peninsula. The reasons lie in tin, rivers, harbours and plantations.
Tin in the Kinta Valley and a Muddy Confluence Called Kuala Lumpur
The granite of the peninsula's mountains carried tin, and erosion washed it into the valleys below. The richest deposit lay in the Kinta Valley in Perak, where the Kinta River, a tributary of the Perak River, flows between the Titiwangsa and Keledang ranges. It formed the largest tin field on the tin belt that runs down the Siamese-Malay peninsula, and its mines were among the most productive in the world. Indigenous miners had worked it since ancient times, and Mandailing migrants from Sumatra dug pits there in the 19th century, but the first great rush came between 1884 and 1889, when Chinese miners from Guangdong took up new land with hoes, baskets and water wheels.
In 1913 Malayan Tin Dredging introduced the floating bucket dredge, and the method came to dominate the valley. The surviving Tanjung Tualang Dredge No. 5, built in England in 1938 and weighing 4,500 tonnes, worked for 44 years until the tin price collapse closed it in 1982. The old workings are now ponds, and Ipoh, the city tin built, anchors a conurbation of 1.28 million people (2020), Malaysia's fourth-largest. The valley's limestone hills and mining landscape were declared the country's second national geopark in 2018.
Further south, tin made the capital. Kuala Lumpur grew from about 1857 as a supply town for mines up the Klang River, at the point where the Gombak joins the Klang. Its name means "muddy confluence" in Malay, kuala being the meeting of two rivers and lumpur meaning mud. It became the capital of Selangor in 1880 and later of the federation, and Greater Kuala Lumpur, which includes the Klang Valley, had about 8.81 million people in 2024. Even so, the government's executive and judicial branches moved to the planned city of Putrajaya in 1999. The Kuala Lumpur capital city guide covers how the town became a metropolis.
The Strait of Malacca Coast, from Penang to Port Klang
Geography gave the peninsula's west coast every advantage. Its good natural harbours are on the western side, the most fertile land lies where rivers reach the sea, and the coastal plains facing the Strait of Malacca are the most densely populated part of the country. The strait between Sumatra and the peninsula is arguably the most important shipping lane in the world, and the sea boundary down its middle was fixed with Indonesia by a 1970 treaty.
The main port is Port Klang, 38 km southwest of Kuala Lumpur. Known in colonial times as Port Swettenham and renamed in 1972, it grew from the rail link that Frank Swettenham, Selangor's British Resident from 1882, built to carry tin from Kuala Lumpur to the coast, and it ranked as the world's 14th-busiest container port in 2022. Further north, Penang Island, 295 km² and home to 794,313 people in 2020, has a hilly forested interior rising to 833 m at Penang Hill, which squeezes George Town onto the narrow plain of the northeastern cape and has pushed the city into land reclamation. At the far south, Tanjung Piai in Johor is the southernmost point of continental Eurasia, and the narrow Straits of Johor form the maritime border with Singapore, which separated from the federation in 1965.
The Titiwangsa Range, the Cameron Highlands and the Pahang Lowlands
The Titiwangsa Mountains run north to south down the peninsula, mostly granite and heavily forested, and divide it into a west coast and an east coast that face different seas and different weather. More than half of the peninsula lies above 150 m. The highest peak, Mount Tahan at 2,187 m, stands on the separate Tahan Range inside Taman Negara, where a return trip on the classic trail typically takes seven days.
Behind the mountains, the east coast faces the northeast monsoon, which blows from October to March and brings more rain than the southwest monsoon; Kota Bharu in Kelantan once recorded 608 mm in a single day in January 1967.
The heights also offered relief from the heat. The government geologist William Cameron mapped the Pahang–Perak border area in 1885 and reported gentle slopes and plateau land; in the 1930s the colonial authorities developed it as a hill station. The Cameron Highlands district covers 712 km² at elevations from 800 to 1,603 m, about 200 km north of Kuala Lumpur, and its cool, cloudy slopes are covered with tea estates, vegetable farms and nurseries that supply the lowland cities.
Rubber, Oil Palm and the FELDA Settlements of Pahang
The same highlands feed the peninsula's longest river. The Pahang River rises as the Jelai on the upper slopes of the Titiwangsa near the Cameron Highlands, joins the Tembeling, and flows 459 km through Jerantut, Temerloh and Pekan to the South China Sea, draining almost all of Pahang. Its broad lowlands became the main stage for Malaysia's planned land settlement scheme, and Pahang still holds more of its colonies than any other state, centred on the Jengka scheme, with some 43,000 settlers.
The Federal Land Development Authority, FELDA, was formed on 1 July 1956 to clear land and settle the rural poor as smallholders. Its first colony opened in 1958 at Lurah Bilut near Bentong in western Pahang and grew rubber. From 1961 the schemes switched increasingly to oil palm to avoid dependence on rubber prices, and by 2000 about 76 percent of FELDA land was under oil palm. Between 1958 and 1990 more than 112,000 settlers moved into its colonies, each typically given 10 to 14 acres. FGV Holdings, the company FELDA later spun off, is considered the world's largest plantation operator, with about 811,000 hectares of oil palm.
Sarawak's Rajang River and the Longhouse Interior
Across the South China Sea, East Malaysia is larger but has only two major cities, Kuching and Kota Kinabalu. Southern Sarawak is mostly coastal lowland, rising northwards through plateaus to the mountains of the interior. Kuching is the wettest place in Malaysia, averaging 4,159 mm of rain over 279 days a year, and that water drains to the sea through long, navigable rivers that for centuries were the only roads.
The greatest is the Rajang, which rises in the Iran Mountains near the Indonesian border, passes Kapit and Sibu, and reaches the South China Sea after about 565 km, making it the longest and largest river by volume in Malaysia. Its vocabulary records how people settled it. A main river is a batang, a trunk fed by smaller sungai; upriver country is the ulu; Iban longhouse settlements where tributaries join the main stream are named nanga, followed by the river beside them; and the Orang Ulu use long for the confluences where they built.
Sarawak's interior now carries a heavy industrial imprint. The Bakun Dam on the Balui tributary, online since August 2011, is designed to generate 2,400 MW. Logging since the 1960s has felled more than 80 percent of Sarawak's forests, polluting rivers and increasing erosion. In the north, Miri was founded in 1910 when Royal Dutch Shell drilled the first oil well there, the start of the Malaysian petroleum industry, and it is also the gateway to Gunung Mulu National Park, whose limestone holds the Sarawak Chamber, about 700 m long and among the largest cave chambers known.
Sabah, Mount Kinabalu and the Borneo Borders
Sabah is the most mountainous state. The Crocker Range runs down its length and splits it in half, carrying Mount Kinabalu, whose summit, Low's Peak, was re-surveyed by satellite in 1997 at 4,095 m, about 6 m lower than the long-published figure. Kinabalu is a geologically young granodiorite pluton pushed up through folded sediments, and it is the highest mountain in Maritime Southeast Asia. Its slopes, protected in Kinabalu Park, a World Heritage Site, hold an estimated 5,000 to 6,000 plant species, and the summit is the one place in Malaysia where snow has been recorded, a handful of times since 1975, most recently in 2022. Mount Trus Madi, the country's second-highest peak, is also in Sabah. So are Bombalai Hill, the only volcano in Malaysia classed as active, and Banggi Island, at 440.7 km² the largest island lying wholly within Malaysian territory.
East Malaysia's mountains also make its borders. The highest ranges in Borneo form the frontier between Malaysia and Indonesian Kalimantan, while to the north Sarawak shares a land border with Brunei. Sabah's northeast coast faces the Sulu Sea and its southeast coast the Celebes Sea, waters shared with the Philippines and Indonesia. Our guide to the countries that border Malaysia sets out each land and sea frontier, and the Borneo island geography guide places Sabah and Sarawak within the whole of the world's third-largest island.