Auckland is the largest city in New Zealand (more than one million inhabitants) and plays a large economic role. It is located in the country's North Island, and has a large airport with flights to Australia, Hong Kong, Japan, Singapore and the U.S. west coast.
Visiting New Zealand with Auckland as your first visit is very good idea. That way you cross the country from north to south, first discovering the North Island and then taking a ferry to the South Island.
One of the best things about Auckland is the diversity you see on the streets. The people fare rom diverse backgrounds, especially European, Asian and Maori. A fun side note about the city is that, some parts of the famous film trilogy "The Lord of the Rings" was filmed on the outskirts of AUckland.