All around Panau there are new locations to discover. These will be bases, towns, villages, airports & other random places. To discover a location all you have to do is enter its vicinity, when you do you will see Location Discovered come up on your screen. If you open up your PDA undiscovered locations will appear as yellow glowing dots. Once you have discovered a place it will become a black square and the icon in it will represent the place, for example an airport location has a plane icon.

Altogether there are 368 locations, just discover 100 and the trophy is yours.