You can get into New Zealand solely by plane.
New Zealand is a long way away from most other countries. So, the only practical way to get in is by plane. Even then, flights are said to take up to 3 or more hours to get to New Zealand, and we're talking about the shortest distance, say from Australia to here. The three major airports are Auckland International Airport, Christchurch International Airport and Wellington International Airport. There are direct flights to and from Fiji, Samoa, Tonga and Cook Islands. Direct connections are also offered from Christchurch to Melbourne, Sydney, Brisbane and Singapore. If taking a flight from Australia, you will require a transit visa.