Characters in the game can use an informations gathering order, to collect information about any region of the map - representing the gathering of information from traders, sending out of spies, etc. In general, areas adjacent to your armies/territories will be "visible" - in addition, the player will also receive information from areas with lots of traffic (i.e., trade centers), and areas which are symphatetic to the player side (e.g. the people of the area support the player's country either due to being culturally related, or having been previously owned by the player).