It’s on the outskirts of Helensburgh Berty - it actual runs up to overlook Faslane Naval Base - the one with the nuke subs. I currently live 10 mins cycle from it. It’s been my route of choice for over six years. About 8 miles long and rarely visited by cars. There’s arguably a better Glen a little more north called Glen Douglas. Very Very pretty ride...... and closer to my new house.