If you're after some wilderness, visit Kaitoke Regional Park, which is about 40 minutes drive from the city centre. Beautiful scenery, native bush, walks, river to swim in. Divine!
Within the city itself is Karori Wildlife Sanctuary. There are plenty of walks, and it's a great opportunity to see some of the rarer birds (and other wildlife) of New Zealand in a natural setting (there are no cages. The birds come and go as they please).
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