Mt. Suribachi, the 550-foot volcanic cone at Iwo's southern tip, dominates both possible landing beaches. From here, Japanese gunners zeroed in on every inch of landing approach. Pillboxes flanked the Marines' landing areas. Within, more heavy weapons stood ready to blast the attacking Marines. Machine guns criss-crossed the beaches with deadly interlocking fire. Rockets, anti-boat and anti-tank guns were trained on the beaches. Every Marine, anywhere on the island, was always in range of Japanese guns. Marines had to root out their foes inch by inch.