If you go to a big city, you will find many theme attractions, such as Rainbow s End in Auckland, Fantasy Land in Hastings, Marine Land in Napier, and the International Antarctic Centre in Christchurch. At the National Museum of New Zealand (Te Papa) in Wellington, there are more family-friendly activities.
Biggest amusement park in Auckland
Amman Street is a busy choice. It's busy during the day, busy during the weekend and crazy crowding (Thursday to Friday). There are many restaurants nearby, hookah bars (water pipes), etc. Most importantly, there are many antique shops here. I would definitely recommend it. It's very colorful and lively. Many locals and tourists are very crowded.
In Auckland, the only large amusement park is still very happy.
Personally I don't like this place but if you need a theme park here it is...