there are cordinates from the map of the place you are. Go to a place's page and look for the map, you can notice that the map is grided and there are some number and letters on that boarders. You can calculate the cordinate from there.
This cordinates are from maps on Wikia only. In game there is no cordinate or grid on map. (ie. On wikia go to The Fourth Path page and look to the map on the right, you can expand it to see better. if there is a treasure chest (C-5) it's indicates that it is in position C-5 on map in wikia.)