The Ngauranga Gorge is in the Wellington Region of New Zealand. State Highway 1 runs through the gorge, a vital link between central Wellington City and its northern suburbs and Porirua City and the Kāpiti Coast; it is the main route north out of Wellington. It is 2 kilometres (1.2 mi) long and has a grade of approximately 8 percent. Sixty-five thousand vehicles a day travel through it, and it connects the Wellington Urban Motorway with the Johnsonville–Porirua Motorway.

State Highway 1 is the longest and most significant road in the New Zealand road network, running the length of both main islands. It appears on road maps as SH 1 and on road signs as a white number 1 on a red shield, but it has the official designations SH 1N in the North Island, SH 1S in the South Island.