And each has unparalleled collections of art, history, natural history and so on, as well as large temporary exhibition facilities.
Museums and galleries depend heavily upon their temporary exhibitions to maintain their audience's interest. The number of highly profiled exhibitions a community can absorb is finite.
What Auckland Museum and Auckland Art Gallery need least of all is a lavishly funded competitor arriving on their patch, stripping them of audience and reducing their visitor numbers. There is no way that the enthusiasm for a Te Papa annex in Auckland can avoid the inevitable fact that it would diminish attendance at the city's own fine institutions.
And it should not be forgotten that people coming to our museum or art gallery inevitably use their time there to take in other exhibitions, their permanent collections, and to patronise their shops and cafes.
A Te Papa North facility would recycle exhibitions into the larger Auckland audience from Te Papa in Wellington, and would inevitably do so at the expense of our own museums.
There is still a feeling in Auckland that Wellington received all of Government's largesse and that Auckland, the major source of the nation's taxes, missed out. Well, yes, that's true. But do we imperil our own institutions in order to make a late grab for Government dollars?
The argument has been raised before, again in support of Te Papa North, that only a tiny portion of the national collections are shown at Te Papa and that this will allow more to be seen, and to be seen up here.
First, Auckland has its own collections - often finer than the national collections. But it is important not to be seduced by silly arguments about only 6 to 7 per cent, or whatever percentage of the collection is shown. Museums and galleries collect for more reasons than exhibition, especially in history and natural sciences.
Their collections are archive and reference collections, held for scientific and scholarly purposes, very often ill-suited or completely unsuited to exhibition. Botanical, biological or geological collections with tens of thousands of small objects are held as important reference stock.
To include such items in an argument about what portion of a collection is exhibited is simply, I'm sorry to say, fatuous. It doesn't begin to be an argument for constructing an Auckland exhibition base for Te Papa.
When the Labour Government started to peddle the South Pacific Cultural Centre idea around the country - an idea that became the Museum of New Zealand, and then was branded Te Papa - Auckland City Council, with support from other centres, proposed a new national museums service that would combine the resources of Auckland, Wellington, Christchurch and Dunedin's four large museums and four art galleries, grouped under a central secretariat, funded part regionally and part centrally, to deliver a comprehensive service throughout the country and tour exhibitions and collections nationally while drawing upon the lion's share of our national patrimony.
Of course, that idea didn't suit Wellington's ambitions to build a new monument for that city. And, more recently, when ideas were mooted to build a new art gallery on the Auckland waterfront rather than extend a constrained building on an even more constrained site, pragmatism got in the way, and that opportunity was also lost.
But are those reasons to clutch at the straw of an exhibition annex for Te Papa as a way of plugging into Government funding and generating a building for our prime harbour-front site? No, what is required is vision for what might be.
Government's priority for the immediate future is rebuilding Christchurch. But when that pressure eases, and when the tank farm land becomes available, the obvious choice is for a large, new, innovative national museum of contemporary art.
New Zealand has no international-scale centre for the exhibition of current art.
This should be it - bold, provocative, widely appealing. Energetic and international - a place to focus attention on current New Zealand art and exhibit the best of international art. And if we want an example of how that might be, we only have to look to Brisbane and its magnificent new Gallery of Modern Art.