Auckland is the largest and most populous urban area in the country, but not the capital (Wellington). 1/3 of New Zealand's population lives here. Auckland is a great location if you like sailing. You can also jump from the TV-tower - attached to a rope...
Christchurch is the largest city on South Island. The city was hit hard by two earthquakes in 2010 and 2011 (magnitude 7.1 and 6.3) that killed 185 people. The damage is still very visible in the city center where real ruins and abandoned buildings are now neighbouring brand new offices and restaurants.
A Scottish city in the far South of NZ, where the Otago Peninsula (with lots of flora and fauna, incl,. Albatros, Penguins and Sealions) plus the bars are the main attreaction.
Milford Sound Fjord is one of New Zealand's most famous tourist destinations and a world heritage site.
Rotorua is best known for the underground geothermic activity, like hot springs, geysirs and mud pools. Even the soil on the camp ground may be "warm"... The tourism industry is by far the largest industry in the district.
Wellington is the capital of New Zealand, but not the largest city. Located at the far bottom of Nort Island, most people will pass here when crossing between both islands.
Wellington is close to the home of the Hobbits, some of the smallest people in the film industry (The Lord of the Rings). Thee is also a nice funicular train ride.