Look at the cranes from the center of the map, then to the left side of the map. Go to that side's back left corner. You will see broken scaffolding. Sprint from before the ledge and jump to the left outside yellow railing. Note: The railing is vertical. Climb up the hidden railing/ladder to the top of the scaffolding, then walk to the right of the scaffolding along the ledge of the building. You will eventually reach another scaffolding. Climb onto this scaffolding and walk to the top. Look towards the building and climb onto the higher ledge, then follow that ledge going left. Keep going forward and you will reach the roof. This is a very good sniper position. You may want to bring a Tactical Insertion because other players may discover you on your way to the top, or while you are up there, and toss grenades.