if you find the ben nevis campsite about 5 miles out of fort bill then stay on that road following the river you will come to a bridge about 5 miles past the campsite. it is a single track bridge and is just there. it is good fun but make sure you jump into where the water is foamy. have fun
oh i think i have been up there before and my friend jumped off but prob just a bit further down or up from where you are. defo going there though cant wait cheers x