by Aliya Whiteley

Just when you think there's nothing new to be seen, done, or explored upon this Earth, you get reminded how vast and unconquerable the planet actually is. For instance, no matter what the Mother Superior sings in The Sound Of Music, we are far from climbing every mountain. There are plenty of unclimbed mountains in the world for a number of reasons; we don't even know for sure how many, since the historical record is vague.

But there's general agreement that Gangkhar Puensum, the highest mountain in Bhutan at 24,836 feet and the 40th highest mountain in the world, can probably be described as the highest unclimbed mountain. Why hasn't it been climbed? That's partly due to its incredibly remote nature, and the fact that despite its size, it was, for quite some time, difficult to find. It was first mapped in 1922, but later maps marked it in different positions, and at various heights. Bhutan has never conducted its own official survey.

But now we have satellites and GPS—so surely it should be easy to track down and climb, right? Well, Gangkhar Puensum also lies in disputed political territory, on the border between Bhutan and Tibet. Bhutan says the mountain is entirely within its territory, but China claims that half of it lies in Tibet, and is therefore Chinese.

Add to this disagreement the fact that in 1994 Bhutan banned the climbing of all mountains higher than 19,800 feet out of respect for local religious beliefs—and in 2003 prohibited mountaineering entirely—and you have a lot of reasons why Gangkhar Puensum remains unclimbed. It's not that people haven't tried; for instance, there were four expeditions in the 1980s that were all unsuccessful.

The last attempt made on the mountain didn't even reach it; China gave permission for a Japanese expedition to attempt Gangkhar Puensum in 1998, and Bhutan then revoked the permit. Eventually the expedition went off and climbed a nearby mountain instead. It's called Liankang Kangri, lies in Tibetan territory, and is a subsidiary peak of Gangkhar Puensum that is only a few hundred feet smaller. Guess what? Before the Japanese expedition was successful in its climb, that mountain was unclimbed too.