Gangkhar Puensum

Gangkhar Puensum (གངས་དཀར་སྤུན་གསུམ་, alternatively, Gangkar Punsum or Gankar Punzum) is the highest mountain in Bhutan and the highest unclimbed mountain in the world, with an elevation of 7570 m and a prominence of 2995 m. In Dzongkha language, its name means "White Peak of the Three Spiritual Brothers".

Gangkhar Puensum lies on the border between Bhutan and Tibet. After Bhutan was opened for mountaineering in 1983, there were four expeditions that resulted in failed summit attempts in 1985 and 1986. In 1999, a Japanese expedition successfully climbed Liankang Kangri, a 7535 m subsidiary peak (not an independent mountain), separated from the main peak by a 2 km long ridge to the north-northwest but had to turn around when their permit was revoked.

In 1994 Bhutan banned the climbing of peaks over 6,000 metres and since 2003, all mountaineering has been banned in Bhutan.

History
The elevation of Gangkhar Puensum was first measured in 1922 but, until recent years, maps of the region were not at all accurate and the mountain was shown in different locations and with markedly different heights. Indeed, because of inadequate mapping, the first team to attempt the summit was unable to find the mountain at all.

The book of the 1986 British expedition gives the mountain's height as 24770 ft and states that Gangkhar Puensum is completely inside Bhutan, whereas the nearby Kula Kangri is completely inside Tibet. Kula Kangri, 7,554 metres, is a separate mountain 30 km to the northeast which was first climbed in 1986. It is variously mapped and described as being in Tibet or Bhutan.

Since 1994, climbing of mountains in Bhutan above 6,000 m has been prohibited out of respect for local spiritual beliefs. Since 2003, mountaineering has been forbidden completely.

In 1998, a Japanese expedition secured permission from the Chinese Mountaineering Association to climb the mountain, but permission was withdrawn because of a political issue with Bhutan. Instead, in 1999, the team set off from Tibet and successfully climbed the 7,535-metre subsidiary peak Liankang Kangri (also known as Gangkhar Puensum North).

Unlike most maps, the expedition's report shows this summit as being in Tibet and the China–Bhutan border is shown crossing the summit of Gangkhar Puensum, described as "the highest peak in Bhutan", at 7,570 metres.