Just a little FYI about maps. Google maps allows you to download maps for free for a month or 2, and that should include POIs, businesses, etc.
There's also another maps app I would HIGHLY recommend, called what3words - https://what3words.com
One of the cleverest things I've ever seen, it makes communicating location insanely easy. I was introduced to it by a ex gfs uncle - smartest guy I ever met, and he loved finding new clever things.
Ahh, the official 'address' system of the Mongolian Post Office?