In order to uncover new map areas, you need to climb radio towers. On the top, there always is a wire box, whose opening, and disabling the encoder, uncovers a fragment of the map, and marks points of interest. The player is rewarded with unlocking new free weapons in shops, and enrichment of the stock. Before you take to the exploration of a given area, it is a good idea to climb the nearest tower to uncover it. Thanks to that, you won't have to explore blindly.
Every radio tower is a challenge and there are different obstacles on your path towards the tower. In most cases, the entrance is at the foot of the tower. There is a mast, the first floor of which you can reach only by using the nearby zip line. The way up requires jumping over holes and climbing. Often, you will have to walk to the other side of the mast over thin elements of the structure, shown in the screenshot, At all times, keep your eyes open for ropes hanging down, or other elements that you can use to climb higher.