Bluff, previously known as Campbelltown and often referred to as "The Bluff", is a town and seaport in the Southland region, on the southern coast of the South Island of New Zealand serving as the main port of Invercargill. It is the southernmost town in mainland New Zealand and, despite Slope Point and Stewart Island being further south, Bluff is colloquially used to refer to the southern extremity of the country.