The Auckland isthmus, also known as the Tāmaki isthmus, is a narrow stretch of land on the North Island of New Zealand in the Auckland Region, and the location of the central suburbs of the city of Auckland, including the CBD. The isthmus is located between two rias : the Waitematā Harbour to the north, which opens to the Hauraki Gulf / Tīkapa Moana and Pacific Ocean, and the Manukau Harbour to the south, which opens to the Tasman Sea. The isthmus is the most southern section of the Northland Peninsula.
The Auckland isthmus seen from the International Space Station in 2019
Almorah Rock Forest, an ecosystem that once covered much of the Auckland isthmus (pictured: lava rock forest remnant at Withiel Thomas Reserve, Newmarket)
Wetlands and swamps surrounded by Cordyline australis (cabbage trees / tī kōuka) formed in many of the unforested areas of the isthmus (pictured: Cabbage Tree Swamp in Sandringham, circa 1910)
Kūmara (sweet potato) was widely grown on the isthmus during the pre-European period, and stored in rua kūmara (storehouses) (pictured: storehouse pit remnants on Ōhinerau)
Auckland is one of the 16 regions of New Zealand, which takes its name from the eponymous urban area. The region encompasses the Auckland metropolitan area, smaller towns, rural areas, and the islands of the Hauraki Gulf. Containing 33 percent of the nation's residents, it has by far the largest population and economy of any region of New Zealand, but the second-smallest land area.
True-colour image of the region showing the Auckland urban area as the brownish area just left of centre, with the Hauraki Gulf to the right
