Another thing that can make country-hopping a bit difficult is making phone calls — yes, phones are still necessary for travel today. Specifically, knowing what country code to use. This becomes increasingly important to know when you’re traveling through tightly packed countries. Here is an infographic for Asia.

It might look a little confusing at first, but once you’ve familiarised yourself with the map, you’ll see it’s simple. No matter whether you’re traveling from Russia to India or from Indonesia to Japan, this map will have you covered.