If you want to fast level your Survival skill tree in Dying Light, we have the solution for you, although this won’t be much fun at all. As you can watch in the video below, what you need to do is to go in the old city of Harran, specifically, at the point, you can see detailed on the map in the first second of the clip, and look at the Rais drop which is there.
Killing the guys who are defending the drop will grant you 5,250 survival experience points and delivering the drop to the quartermaster will provide you with additional 11,200 points.
Once you complete the killing, all you need to do is go to the quarantine and exit. You will notice at that specific point there is still a drop and people defending it. Kill them all every time you want and get all the experience points you can get before leaving the place.