The Kawana Mill at Matahiwi has the only surviving set of mill machinery dating back to the 1850s in New Zealand. It was the longest-operating mill on the Whanganui River. The mill was established on land belonging to the Whanganui iwi Nga Poutama, as part of Governor Sir George Grey's initiative to encourage Maori to learn skills to become self-sufficient in a Pakeha economy. In August 1854 Reverend Richard Taylor, Church Missionary Society, the millwright Peter McWilliam, and local Maori built the mill from totara logs salvaged from the Whanganui River. The cast-iron machinery and brass bearings were brought out from England and the millstones were imported from Australia. The millstones were a personal gift of Grey, and as a result the mill was named using a transliteration of its benefactor's name - Kawana Kerei. The first miller was Richard Pestall, an appointee of the New Zealand Government and Governor Grey, and, on his retirement, his second son Richard continued running the mill until it ceased operations in 1913. During the 1930s the top stories of the building were dismantled and the iron used for the Matahiwi School.

The present building is a reconstruction undertaken between 1978-1980 by members of the local tramping club and the then Wanganui regional committee of the New Zealand Historic Places Trust. The restoration work included moving the miller's cottage alongside the mill (see Kawana Miller's Cottage, registered Historic Place, Category I). The Governor General, Sir Keith Holyoake, officially re-opened the mill in October 1980 and over 600 people attended the ceremony. The land on which the mill is sited was designated a Maori Reserve for historical purposes in 1986. Today the mill is a tourist attraction with photographic displays relating to the history of the site.

This mill has great historical significance as the site of one of Governor Grey's initiatives to encourage Maori to become economically self-sufficient. The surviving elements of the mill, essentially its machinery, are important relics of that period. The reconstructed mill has considerable educational value for its demonstration of nineteenth-century industrial technology that was once a common site along the Whanganui River. The relationship between the mill and local iwi is a strong one, founded on the nearly 60 years that it operated within the Maori community.