Passing locations \\ cities \\ villages (Just Cause 4)

The bottom line is this. I just can't understand what needs to be found / destroyed, etc. to open a city / village.
On the map, when you hover over the icon of a city or village, you need to do some action to open it 100%. Blow up the Derijable, for example. But what else needs to be done to make it 100% ??