The GR 20 is a world-famous trail that traverses through much of Mediterranean island of Corsica, off the coast of southeastern France. It is very strenuous route through high mountains, and can be very dangerous in severe weather. The trail contains mountain hut shelters for hikers. Despite its relatively short length, the GR 20 is considered to be a very difficult hike to complete. The mountainous terrain is very challenging, even for very experienced hikers. However, the popularity of this trail also means certain factors are easier, such as navigation and transportation arrangements.