Just commented here as my comment would've lost in the others in Annapurna video It is named Annapurna --> 'Anna Purna' for a reason Just a dumb thought but how about bringing sky glider type jackets and parachutes on certain mountains where after ascending you can find a location and just parachute off or on a slopy area just start skiing down and then pull the parachute at the end of the slope if such locations can be found on the mountain.
So the mountain coaster would be the longest right? By definition it is a roller coaster. They are also accepteted as such by the American Coaster Enthusiasts club.
