The Martintown Grist Mill is architecturally significant as a rare surviving example of a substantial, mid-19th century, Ontario grist mill located on the banks of the Raisin River in Martintown. Of the large number of mills built in Ontario in the 19th century, the Martintown grist mill is more substantial than many, being constructed entirely of stone. Comparatively, most Ontario mills were built of wood or a combination of wood and stone. Devoid of an external water-wheel, the Martintown Grist Mill is also notable as an early Ontario mill to take advantage of early turbine style technology that utilized horizontal water-wheels, powered by a water course running through the bottom of the building. Initially appearing in Canada in the 1840s, these internal, submerged water-wheels had the advantage of being unaffected by seasonal floods, low volumes of water and freezing weather, thereby remaining ice free. The Mill has a local history museum and hosts a farmers market and local artist exhibit in the summer on Sundays from 25 June to 17 Sept.