The position of Wellington as capital of New Zealand is not defined in legislation, but established by convention. Its metropolitan area comprises four local authorities: Wellington City, on the peninsula between Cook Strait and Wellington Harbour, contains the central business district; Porirua City on Porirua Harbour to the north is notable for its large Māori and Pacific Island communities; Lower Hutt City and Upper Hutt City are largely suburban areas to the northeast, together known as the Hutt Valley. These four cities are considered large parts of Wellington, but are governed separately. The Wellington urban area, which only includes urbanised areas within Wellington City, has a population of  residents as of . The urban areas of the four local authorities have a combined population of  residents as of .