If you get to spend time in Auckland then there are some good walking options in the city itself. We rented an apartment in the Viaduct for eight days or so and rather enjoyed city life.
The Skywalk is an old motorway on-ramp that is now disused. It has been painted a bright pink and is a shared walk and cycleway that gives good and unusual views of the city. From the viaduct head up Hobson Street and follow the Skypath to link up with the tracks down to Grafton Gully.
From the bottom of the gully you could turn right and go for a swim in the saltwater swimming pools of Parnell, highly recommended. The walk takes a couple of hours at most and gives you a real flavour of the CBD. Auckland is not as bad as those who do not live there paint it.