The Achtkante Mill is a historic polder mill located on Molenkade in the town of Groot-Ammers. It was built in 1805, to replace an older mill which had burned down in 1805. The mill was damaged by a low flying aircraft during the Second World War. In 1972, major restoration work was carried out on the mill, and it was re-opened with a ceremony presided over by Mayor H. Boer of Groot-Ammers. The mill is not currently open to the public.