A proposal to merge the region's four councils into one could have the surprising consequence of making Northland more than 50km longer.
The expansion of Northland's territory would come about because the proposed Northland Council would take in the Three Kings Islands, a cluster of 13 rugged islands 55km northwest of Cape Reinga.
According to the draft proposal for reorganising Northland's local government, released by the Local Government Commission on Tuesday, a single Northland District would include the Three Kings.
Although relatively close to the mainland, the islands are not currently part of any territorial authority.
They are classified as outlying islands and administered directly by the Minister of Local Government while the Department of Conservation is responsible for enforcing the Building Act on the rocky outcrops.