Aonach Eagach
Scrambling, which is a term used to describe climbing over rough ground, is necessary to complete Aonach Eagach, which is in Scotland. It’s grade two scramble, so you need some sort of experience. The spine-tingling drops and exposure to the elements, like weather and danger, makes it one of the most treacherous hikes in the world. It’s only six miles long, but because of its many downward manoeuver’s and upward scrambles, it’s one of the most terrifying treks you can embark on. You need a lot of vigilance and concentration to complete the trek (Wired for Adventure).