Puncak Jaya sometimes called Mount Carstensz or the Carstensz Pyramid, is a mountain in the Sudirman Range, the western central highlands of Papua province, Indonesia. Other names include Nemangkawi in the Amungkal language, Carstensz Toppen and Gunung Sukarno.
Puncak Jaya is the highest mountain in Indonesia, the highest on the island of New Guinea (which comprises the Indonesian Papua provinces plus Papua New Guinea), the highest on the Australia-New Guinea continent and the highest in Oceania. It is also the highest point between the Himalayas and the Andes and the highest island peak in the world.
When Indonesia took control of the province in the 1960s, the peak was renamed 'Puntjak Soekarno' (Simplified Indonesian: Puncak Sukarno) or Sukarno Peak, after the first President of Indonesia, later this was changed to Puncak Jaya. Puncak means peak or mountain and Jaya means 'victory', 'victorious' or 'glorious').
While Puncak Jaya’s peak is free of ice, there are several glaciers on its slopes, including the Carstensz Glacier and the Northwall Firn. Being equatorial, there is little variation in the mean temperature during the year (around 0.5°C) and the glaciers fluctuate on a seasonal basis only slightly. However, analysis of the extent of these rare equatorial glaciers from historical records show significant retreat since the 1850s, indicating a regional warming of around 0.6°C per century between 1850 and 1972.
The glacier on Puncak Trikora in the Maoke Mountains disappeared completely some time between 1939 and 1962. Since the 1970s, evidence from satellite imagery indicates the Puncak Jaya glaciers have been retreating rapidly. The Meren Glacier melted away sometime between 1994 and 2000.
Puncak Jaya is one of the more demanding climbs in one version of the Seven Summits peak-bagging list. (It is replaced by Mount Kosciuszko in the other version.) It is held to have the highest technical rating, though not the greatest physical demands of that list's ascents. The standard route is up the north face and along the summit ridge, which is all hard rock surface. Despite the large mine, the area is highly inaccessible to hikers and the general public, requiring a 100-km hike from the nearest town with an airport, Timika, to the base camp, which usually takes about four or five days each way.