Take a look at the map of Dying Light from end to end
The playable area of Dying Light is quite large, let's take a look at just how large it is in this video.
Dying Light is an open-world game. As such, a large, open map is expected.
PlayStation Access has a video available that runs through the whole map to show you just how vast the whole thing is. They also gloss over some of the game's systems and mechanics in the process, so give it a watch.