I'm pretty sure that ACT is the shorthand for Australian Capital Territory. If B.C. is accepted for British Columbia, maybe ACT is okay, too. Hope you're not getting too sick of the praise for these quizzes. Tony the Tiger would endorse you for sure :)
Again, I enjoyed the quiz, but ACT should count. Never heard of Aitutaki Island or Mt. Aspiring. I imagine Mt Aspiring is down Milford Sound area (majestic place)