Millstones inside the Carew Mill. They are surrounded by wooden structures to preserve them. These millstones were used for grinding corn grains. Carew mill is a tidal mill that is driven by the rise and fall of the tide. It was used to produce corn and flour. The mill is situated on the bank of a millpond, which is fed by the Carew river and dates from the beginning of the 19th Century. Photographed at Carew Mill, in Pembrokeshire, Wales, UK.