Auckland Airport (AKL) is 25 kilometres south of the city centre, and is New Zealand's main international gateway. All long-haul flights arrive here, and there are frequent domestic connections to Wellington, Christchurch, Queenstown, and other New Zealand cities.
From the airport, the SkyBus runs express services to the city centre roughly every 10 minutes, taking about 45 minutes depending on traffic — the fare is around NZ$20. Taxis and rideshares are considerably more expensive. The Northern Express bus connects to Britomart if you arrive at the domestic terminal with light luggage.
By train, Auckland is connected to the rest of the North Island via Palmerston North to Wellington, though the journey is long (11 hours). InterCity coaches cover more routes more quickly and are the practical overland option.