What Is the Highest Mountain in Oceania? Puncak Jaya, and Why New Guinea Wins

Puncak Jaya, also called the Carstensz Pyramid, is the highest mountain in Oceania: it rises to 4,884 metres (16,024 ft) in the Sudirman Range of New Guinea, in Indonesia's Central Papua province. No island on Earth has a higher summit, and nothing between the Himalayas and the Andes stands taller. If Oceania is limited to its independent Pacific states, the answer becomes Mount Wilhelm, 4,509 m (14,793 ft), in Papua New Guinea, and if only mainland Australia is meant, it is Mount Kosciuszko at 2,228 m (7,310 ft). The table below ranks the ten highest national high points in the region, and the sections after it explain why the list falls in this order.

Two counting choices shape the table. Indonesia is usually classed as an Asian country, but its provinces on New Guinea sit on the Australian continental shelf, so Puncak Jaya belongs to Oceania in physical terms. France and the United States appear through French Polynesia and Hawaii, and each gets one row, for its highest Pacific summit. Every number on the list comes from one of five mountain-building processes, and they explain the order better than land area does.

New Guinea’s plate collision puts Indonesia and Papua New Guinea first

The top two places, and every summit above 4,500 m in Oceania, are on one island. The New Guinea Highlands, or Central Range, run the length of New Guinea from the Weyland Mountains in the west to Milne Bay Province in the east. They were raised in the late Miocene by an oblique collision between the Australian and Pacific plates, and Puncak Jaya itself is made of middle Miocene limestone pushed up to almost 5 km. The same range carries Puncak Mandala, at 4,760 m the highest point of the Jayawijaya Range, and Puncak Trikora at about 4,750 m, so Indonesia's three highest mountains would also be the region's top three.

Height and latitude together give New Guinea something rare: ice on the equator. The Dutch navigator Jan Carstenszoon reported snow on these peaks in 1623 and was mocked in Europe for it. The glaciers have been retreating since the 1850s, the ice cap on Trikora disappeared between 1939 and 1962, the Meren Glacier below Puncak Jaya melted away between 1994 and 2000, and a 2010 expedition led by Lonnie Thompson measured the remaining ice thinning by about 7 m a year.

Papua New Guinea, independent since 1975, holds the eastern half of the same range. Mount Wilhelm, 4,509 m, is in the Bismarck Range at the point where Chimbu, Jiwaka and Madang provinces meet. The German correspondent Hugo Zöller named it in 1888 after a son of Chancellor Otto von Bismarck, and the patrol officer Leigh Vial made the first recorded ascent in August 1938 with two local companions. Unlike Puncak Jaya, it can be climbed without technical rock work, usually starting at night from the lakes of Piunde and Aunde.

Hotspot volcanoes lift Hawaii, Tahiti and Samoa

Third place goes to the United States because of Mauna Kea on the Island of Hawaii. It is a dormant shield volcano about one million years old, standing 4,207 m above sea level and about 38 m higher than its larger neighbour Mauna Loa. Measured from its base on the ocean floor it rises about 9,330 m, more than the height of Everest above sea level. It was built by the Hawaii hotspot, the plume of hot mantle that also made the 6,200 km Hawaiian-Emperor seamount chain as the Pacific Plate moved over it.

Two more rows on the table come from the same process. Mont Orohena, 2,241 m, is the extinct shield volcano at the centre of Tahiti and the highest point of French Polynesia; the Society hotspot made Tahiti, Mo'orea and Bora Bora, islands between 4.5 million and less than 1 million years old. Mount Silisili, 1,858 m, tops Savai'i, the largest shield-volcano island in the South Pacific, raised by the Samoa hotspot. Its Samoan name simply means "highest". Savai'i is still volcanically active: Mount Matavanu erupted from 1905 to 1911.

The Alpine Fault keeps New Zealand’s Southern Alps rising

New Zealand sits fourth with Aoraki / Mount Cook, 3,724 m, in the Southern Alps of the South Island. The range is being pushed up where the Pacific and Indo-Australian plates meet along the Alpine Fault, a 650 km active fault that runs past the mountain and last ruptured in 1717. Uplift raises Aoraki by about 7 mm a year, yet the peak has lost height in recent times. Surveys in 1881 and 1889 put it at 3,764 m. On 14 December 1991 about 12 to 14 million cubic metres of rock and ice fell from the north peak, taking 10 m off the top, and two decades of erosion of the exposed ice cap removed another 30 m before a University of Otago GPS survey in November 2013.

The Roaring Forties explain its weather. The Southern Alps are the first obstacle the westerly winds meet after crossing the Southern Ocean from South America, and the snow they bring feeds 72 named glaciers, which cover 40% of the 700 km² Aoraki / Mount Cook National Park. Tom Fyfe, Jack Clarke and George Graham made the first known ascent on 25 December 1894, and Edmund Hillary climbed it in 1948, five years before Everest.

Melanesian island arcs: Solomon Islands, Vanuatu and Fiji

Three more rows come from island arcs, chains of volcanic islands built where one plate dives under another. The Solomon Islands are mostly mountainous volcanic islands, and Mount Popomanaseu, 2,335 m, on Guadalcanal is the country’s highest point. Looking east from it across the South Pacific, there is no higher mountain until the Andes. Its saddle-shaped summit plateau can be seen from Honiara International Airport.

Vanuatu lies above a subduction zone where the Australian Plate sinks beneath the New Hebrides Plate along the New Hebrides Trench, more than 7.1 km deep; that volcanism built the archipelago. Its highest point, Mount Tabwemasana, 1,879 m, rises on the remote west coast of Espiritu Santo, and fewer than six people usually reach the summit in a year. Fiji sits in a complex zone between the Australian and Pacific plates. Its highest point, the extinct volcano Mount Tomanivi, 1,324 m, stands in the northern highlands of Viti Levu, the central mountain area where Fiji’s main rivers, the Rewa, Navua, Sigatoka and Ba, all rise.

Why Australia ranks only seventh: Kosciuszko and an old, flat continent

Australia covers more ground than any other country in Oceania, yet mainland Australia's highest point is lower than peaks on Guadalcanal and Tahiti. The reason is stability. Australia is the world’s flattest inhabited continent and sits near the centre of its own tectonic plate, which makes it one of the most geologically stable landmasses on Earth, and some of its rocks are more than 3,000 million years old. It has had no recent collision or hotspot to build high mountains, and erosion has had a very long time to wear down the ones it had. Mount Kosciuszko, 2,228 m, is the top of the Snowy Mountains, part of the Great Dividing Range in New South Wales near the Victorian border, and the Snowies hold the country's five tallest peaks.

The Polish explorer Paweł Strzelecki reached the summit area on 12 March 1840 and named the peak after Tadeusz Kościuszko; in 2019 the Ngarigo name Kunama Namadgi was proposed as a dual name. Today a 5 km mesh walkway from the Thredbo chairlift leads to Rawson Pass, 1.4 km short of the summit. Australia does have a higher mountain, but not in Oceania: Mawson Peak on Heard Island, an Australian external territory in the Indian Ocean, reaches 2,745 m, and the volcanoes of Heard and the McDonald Islands are Australia's only active ones.

Puncak Jaya or Kosciuszko: how politics shaped the Seven Summits

The question of Oceania's highest mountain matters most to climbers chasing the Seven Summits. When Richard Bass became the first person to climb all seven, on 30 April 1985, his list used Kosciuszko, a walk rather than a climb. Reinhold Messner's version swaps in Puncak Jaya, which counts New Guinea as part of the Australian continent and makes Oceania's summit the most technical of the seven. Other lists use Mount Wilhelm, the highest point of Oceania by present political boundaries if Indonesia is counted with Asia.

Politics also explains Puncak Jaya's names. The Dutch called it the Carstensz Pyramid, and their 1936 expedition of Anton Colijn, Jean Jacques Dozy and Frits Wissel reached the glacier-covered Ngga Pulu summit, then probably the highest at over 4,900 m, but not the bare rock pyramid. Heinrich Harrer, Philip Temple, Russell Kippax and Bert Huizenga made the first ascent in 1962, the same year the Netherlands agreed to hand Western New Guinea to a UN administration; Indonesia took over in 1963, and the peak's Indonesian name means "victorious peak". The open-pit Grasberg gold and copper mine lies 4 km to the west, and climbers need a government permit; the mountain was closed to them from 1995 to 2005. For the wider debate over where Indonesia and Papua New Guinea belong, see our guides is Indonesia in Asia or Oceania and how many countries are in Oceania, and for the fourth-placed peak, our full Aoraki / Mount Cook guide.