What is the Military Base (Citadel), how do I get inside, and how does the radar work?

The Military Base — shown on the map as Citadel — is the most dangerous location on the island, and the loot matches the risk.

• It's patrolled by armed guards. You can tell their rank by armour colour: green — the easiest, blue — tougher, red — the hardest. Don't come with a bow or spear: bring good weapons, plenty of meds and ideally a team.

• An anti-air turret on the base shoots at helicopters.

• Killing a guard has a chance to drop a Military Base Keycard. It can't be crafted.

• Take the keycard to the radar in the centre, climb to the roof from the outside and insert it into the Access Terminal. The keycard is consumed.

• The dish activates and calls airdrops onto the base — everyone nearby is notified, so expect company.

• After that the radar goes on cooldown — if you try to activate it during that time, you'll see a "system recharging" message.

• It's patrolled by armed guards. You can tell their rank by armour colour: green — the easiest, blue — tougher, red — the hardest. They walk fixed routes, stop at points to watch the area, use cover, throw smoke grenades and return to patrolling once a fight is over. They keep scanning the area even while standing still, so they'll spot you before you're in their line of sight. Don't come with a bow or spear: bring good weapons, plenty of meds and ideally a team.