The 'Achtkante Molen' (eight-sided mill) in Groot-Ammers stands out because of its shape among the windmills that are located along the watercourse. The mill was placed in 1805 to replace a wipmill, which burned down earlier that year. The 'Achtkante Molen' is equipped with a paddle wheel that is narrower than that of the other mills in the polder, so that the mill pumps the smallest amount of water. The mill was in operation until 1964. The 'Achtkante Molen' was restored in 1972 and 1991/1992 and is draining the Liesveld Polder on a voluntary basis. Owner of the mill is the SIMAV.