Getting the Old Lighthouse Citadel room key in Warzone 2 MW2 might seem challenging, but fear not! Follow these easy steps: 1. Head to Sarrif Bay on the map. 2. Locate the last building on the small island, which happens to be a lighthouse. 3. Enter the lighthouse to find the Citadel room key and collect valuable loot like vests, helmets, health kits, and weapons.