Then, we've got Gangkhar Puensum in peaceful Bhutan, the world's tallest un-summited peak. This is a mountain so nasty that, despite being the 40th-highest overall peak, has never been conquered. Part of that has to do with the fact that the Bhutanese government has had to slap a ban on trying to climb it . They claim it's out of respect for local spiritual beliefs, but according to the chairperson of the Everest Foundation, "They just looked at what was going on in Nepal with Everest and decided that they're not going to be part of that." Gangkhar is too remote and too dangerous, and Bhutan would prefer to remain unknown rather than be known as the place where extreme sports dudebros go to die.