Whanganui (/ˈhwɒŋənuːi/; Māori: [ɸaŋanui]), also spelt Wanganui, is a city on the west coast of the North Island of New Zealand. The Whanganui River, New Zealand's longest navigable waterway, runs from Mount Tongariro to the sea. Whanganui is part of the Manawatu-Wanganui region.

Like several New Zealand centres, it was officially designated a city until administrative reorganisation in 1989, and is now run by a District Council.

Although called Wanganui from 1854, the New Zealand Geographic Board recommended that the name be changed to "Whanganui", and the government decided in December 2009 that, while either spelling was acceptable, Crown agencies would use the Whanganui spelling.
https://en.wikipedia.org/wiki/Whanganui