I think you need to give yourself plenty of time to explore NZ if you go... a week would be really difficult.. you could have fun on one of the islands for a week, but both would be a stretch. And you don't want to just pass by the North Isle just because the South Isle has so many big name attractions, (Queenstown, the Southern Alps, Fiordland etc)... Auckland and further north is full of really cool jungle and amazing beaches and world class diving. And you can "duneboard" up at Cape Reinga, the tippy top. If you like a foodie city, Auckland should be a delight for you. So much diversity! A ton of Japanese influence, Turkish, Indian.. and of course plenty of delish meat pies! As was mentioned earlier, I would recommend delving into the Great Barrier Reef for a bit while you're in Oz... Hamilton Island, (in the Whitsundays) is quite the little gem and perfect jumping off point to explore the reef.

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