When I'm sightseeing I usually like to get a printed map of the city. It is often more useful than a digital map since I usually don't have an Internet connection abroad, besides occasional Wi-Fi, and you can write on it.
The problem is that if I fold the map in the usual way I have to unfold completely to see the area of interest and fold it again, which is not always easy if the map is big. This process is inefficient and time consuming (and sometimes a little bit annoying), just the opposite of what I would want while sightseeing.
I was wondering if there were a better way to fold and unfold maps (namely fast, easy and which doesn't destroy the map).