Three countries share the Malay Peninsula, the long tongue of land that hangs south from mainland Southeast Asia between the Andaman Sea and Strait of Malacca on the west and the Gulf of Thailand and South China Sea on the east. Myanmar holds a sliver on the north-western side that ends at Kawthaung, its southernmost town. Thailand holds the southern provinces from the Isthmus of Kra down, Malaysia holds Peninsular Malaysia (about 131,956 km²), and the island city-state of Singapore sits just off its southern end across the Straits of Johor. A granite mountain chain, the Titiwangsa Range, runs down its centre; the highest point is Gunung Tahan at 2,187 m in Pahang; the longest river is the Pahang at 459 km; and its last point, Tanjung Piai in Johor, is the southernmost point of the Asian mainland.
The Isthmus of Kra, 44 km Between Two Seas
The peninsula's narrowest point is the Isthmus of Kra in southern Thailand. Its western side belongs to Ranong Province and its eastern side to Chumphon Province, and between the towns of Kra Buri and Chumphon only 44 km of land separates the Andaman Sea from the Gulf of Thailand. Just west of that neck, the Kraburi River (the Pak Chan) forms the border between Thailand and Myanmar and widens into a 6 km tidal estuary that holds the largest preserved mangrove forests in Thailand. At its mouth, facing Ranong, is Kawthaung, the town known as Victoria Point under British rule and home to 57,949 people in 2021.
The isthmus also marks a break in the mountain chain that runs from Tibet down the peninsula: north of it are the Tenasserim Hills, south of it the Phuket Range continues the line. Long before canals were proposed, traders carried goods overland here between the Bay of Bengal and the Gulf of Thailand. The historian Paul Wheatley estimated that the portage saved about four months on a voyage between South Asia and China. A canal across the isthmus was suggested as early as 1677, revived in 1793 and in 1859 discussed in a report to the British Parliament on a northern route, but none has been built.
A little further south, a less visible line crosses the peninsula. The Kangar–Pattani floristic boundary, running through southern Thailand and the far north of Malaysia, divides the plant life of Indochina from that of Sundaland. North of it, forests are partly deciduous and shaped by a dry season; south of it, rain falls year-round and the forests are mostly evergreen.
Titiwangsa Range, the Peninsula's Backbone
The Titiwangsa Mountains, known locally as Banjaran Besar (“main range”), are the spine of the peninsula and the southernmost section of the cordillera that begins in Tibet. In Thailand the northern section is called the Sankalakhiri Range and follows the boundary between Yala and Narathiwat provinces; its highest Thai point is Ulu Titi Basah at 1,533 m, on the border with the Malaysian state of Perak. Across the border its main stretch runs north-west to south-east, and in all the range is about 480 km long from north to south, dividing Perak and Selangor on the west coast from Kelantan and Pahang on the east.
The highest summit on the range itself is Gunung Korbu, 2,183 m, about 25 km from Ipoh in Perak. South of Mount Nuang, near the meeting point of Pahang, Selangor and Negeri Sembilan, the range loses height, running through Negeri Sembilan at 500 to 900 m and ending near the town of Tampin. Granite outcrops continue a little further into Malacca state, reaching the sea at the island of Pulau Besar.
Because it splits the peninsula lengthwise, the range is also its main drainage divide, separating the Perak, Klang and Muar rivers in the west from the Pahang and Kelantan in the east. The west side, facing the sheltered Strait of Malacca, holds most of Peninsular Malaysia's people and its major cities, including Kuala Lumpur and Ipoh; the interior is mostly forested and rural. The cool upland of the Cameron Highlands, surveyed by the government geologist William Cameron in 1885, is a 712 km² district on the Pahang side of the range near the Perak and Kelantan borders.
Gunung Tahan and the Forests of Taman Negara
The peninsula's highest mountain does not stand on the Titiwangsa at all. Gunung Tahan, 2,187 m, lies east of the main range in the separate Tahan Range, on the border between Pahang and Kelantan with the summit itself on the Pahang side. It is only 4 m higher than Gunung Korbu. In Malay, tahan means “forbidden”, and a local folk tale says the mountain was guarded by two giant apes; it has also been called Gunung Siam by Kelantanese. The classic trail from Kuala Tahan takes about seven days there and back, and frost occasionally forms on the summit.
The mountain sits inside Taman Negara, a 4,343 km² national park that spans Pahang, Kelantan and Terengganu. It was set up in 1938 and 1939 as King George V National Park after the conservationist Theodore Hubback persuaded the three sultans to set the land aside, and it took its Malay name, meaning simply “national park”, after independence. Its lowland rainforest is often described as more than 130 million years old. Taman Negara is a stronghold for the Malayan tiger and Asian elephant, and lies on the traditional lands of Orang Asli groups such as the Batek, whose use rights are recognised in the park's law.
Across the peninsula, the lowlands are dominated by dipterocarp forest and the mountains above 1,000 m by montane rainforest of beech-family trees, laurels and tropical conifers. Large mammals include the gaur, sun bear, Malayan tapir, clouded leopard and siamang. The Sumatran rhinoceros once lived here too, but Malaysia's last rhinoceroses died in 2019.
The Pahang, Perak, Muar and Kelantan Rivers
The Pahang River, 459 km long, is the longest river on the Malay Peninsula. It forms where the Jelai, which rises on the upper slopes of the Titiwangsa near the Cameron Highlands, meets the Tembeling, which flows down from the Pahang–Terengganu border past Kuala Tahan. From the confluence near Kuala Tembeling, the Pahang runs south through Jerantut and Temerloh, bends north-east at Mengkarak and then east across the floodplains around Pekan to the South China Sea. Its basin covers almost every district of Pahang plus eastern Negeri Sembilan; only Rompin district lies outside it.
The other big rivers sit either side of the divide. On the west, the Perak River, about 400 km long and the second-longest in Peninsular Malaysia, flows past the royal town of Kuala Kangsar; until tin was found around Ipoh in the 19th century, most of Perak's settlements lay along it. The Muar, roughly 250 km, runs through Negeri Sembilan and Johor to the Strait of Malacca. On the east, the 248 km Kelantan River flows north into the South China Sea from a basin of about 11,900 km² that includes part of Taman Negara. Rainfall there ranges from almost nothing in the dry months of March to May to around 1,750 mm in the November–January monsoon.
The Strait of Malacca on the Western Shore
The western coast of the peninsula faces the Strait of Malacca, a channel about 900 km long and between 65 and 250 km wide that separates the Malay Peninsula from the Indonesian island of Sumatra and links the Andaman Sea in the Indian Ocean with the South China Sea in the Pacific. The International Hydrographic Organization draws its western limit from the northern tip of Sumatra to Phuket Island in Thailand and its eastern limit at Tanjung Piai.
It is the main shipping channel between the two oceans. More than 94,000 vessels passed through in 2008, carrying roughly a quarter of the world's traded goods, and in 2024 over 35 percent of seaborne oil and about 20 percent of gas flows used it. Control of the strait has shaped the region's history: Srivijaya, based at Palembang in Sumatra, dominated it from the 7th century, followed by the Malacca Sultanate, the Johor Sultanate, the British Straits Settlements and Singapore. The name comes from the port of Melaka, which tradition says its founder Parameswara named after the Malacca tree he rested beneath.
Mangroves fringe long stretches of both coasts. The Myanmar Coast mangroves ecoregion lines the western shore and the Indochina mangroves the eastern one, and peat swamp forests occupy waterlogged lowlands on both sides.
Johor, Tanjung Piai and Singapore at the Tip
The peninsula ends in the Malaysian state of Johor. Its final point, Tanjung Piai in Pontian District, is the southernmost point of mainland Eurasia, a cape of mangrove forest with 22 mangrove tree species that is one of Malaysia's Ramsar wetlands. From its boardwalks the Singapore skyline is visible across the water.
That water is the Straits of Johor, a narrow tidal channel that separates Johor from Singapore and opens into the Strait of Malacca to the west and the Singapore Strait to the south-east. Two crossings span it. The Johor–Singapore Causeway, 1.056 km long and opened in 1923, links Johor Bahru with Woodlands and carries about 300,000 road and rail travellers a day as well as a water pipeline. The Malaysia–Singapore Second Link, further west between Iskandar Puteri and Tuas, opened on 2 January 1998.
Whether Singapore counts as part of the peninsula depends on the definition. Geographically it is a separate island, usually described as an island country with historical and cultural ties to the peninsula rather than part of the landmass itself. Politically, the borders at both ends of Peninsular Malaysia are recent: the line with Thailand comes from the Anglo-Siamese Treaty of 1909, under which Siam gave up its claims to Kedah, Kelantan, Perlis and Terengganu while keeping Pattani, Yala, Narathiwat, Satun and southern Songkhla, and Singapore, which joined Malaysia in 1963, left the federation to become an independent country in 1965. Singapore itself keeps growing into the sea, with plans to add another 7 to 8 percent to its land area through reclamation by 2030.
The name of the whole landmass in Malay is Tanah Melayu, “the land of the Malays”, a term found in texts from the early 17th century and revived in the name Persekutuan Tanah Melayu, the Federation of Malaya, in 1948. The strait on its western side has its own guide in the Strait of Malacca explained, the channel at its tip is covered in our Straits of Johor guide, and the islands that continue the same geology south and east are the subject of the Malay Archipelago guide.