In the 1930s, part of the fort received modernisation. Then during World War II, it became the administrative centre of Auckland's coast defenses, with the regimental headquarters buildings still surviving today. The coastal defences were scrapped in 1950, though one of the disappearing guns remained behind - obsolete and too difficult for the scrap merchant who bought it to disassemble and remove. After the army had left, the area was turned into a reserve again, though the New Zealand Navy kept an area around the summit for a training school.