Stewart Island has been named as the world's fifth 'Dark Sky Sanctuary'.

Photo: Supplied / Sandra Whipp

The International Dark Sky Association defines a Dark Sky Sanctuary as "public or private land that has an exceptional or distinguished quality of starry nights and a nocturnal environment that is protected for its scientific, natural, or educational value, its cultural heritage and/or public enjoyment".

The association has described Stewart Island's pristine night skies as a rare treasure.

The association said Southland will benefit from a boost in tourism, employment opportunities and a focus on the unspoiled natural environment.

Great Barrier Island is the only other Dark Sky Sanctuary in New Zealand.

The association said a sanctuary differs from an International Dark Sky Reserve because usually it is remote with "few (if any) nearby threats to the quality of its dark night skies".

The process to becoming accredited involved a collaboration between Southland District Council, Department of Conservation, Stewart Island/Rakiura Community Board, Venture Southland, Rakiura Maori Lands Trust, iwi and the Stewart Island Promotion Association.

A Memorandum of Understanding between the key parties has been established demonstrating unified commitment and support for the Sanctuary.