Carew Tidal Mill (), also called the French Mill, is a corn mill in Pembrokeshire, Wales, powered by tidal water. It was built around 1801 just west of Carew Castle, and replaced a much older mill in the same location. The mill pond fills through open flood gates as the tide comes in. The gates are closed at high tide, and the pond drains through sluices under the mill as the tide falls, driving two undershot water wheels. It is the only intact mill of this type in Wales. It was abandoned in 1937, was restored in 1972, and now houses a museum. Location Carew Tidal Mill stands on the south end of a long causeway across the Carew River, a tidal inlet east of Milford Haven. Carew Castle, built in 1270, is to the east. The site of the now ruined castle was occupied by a fort in the Iron Age, and much later by an earth and wood fort built around 1100 by Gerald de Windsor, a Norman. The castle was in turn a military stronghold and a comfortable Elizabethan mansion. A much older mill, which may have been built in the same period as the castle, used to stand at this location. The older mill may have been powered by a leat that ran from the river before the causeway dam was built to create the large tidal mill pond. There are records of the former mill from 1541. The Ministers' Accounts prepared for Henry VIII (r. 1509–47) mention "two mills under one roof called le french mills". The name may derive from the millstones, which were made of French burr stone. John Bartlett took a lease on the mill in 1558 for a fee of 10 sovereigns annually. It was restored in 1792 after a fire. The causeway is first mentioned in a document from 1630 that says that 15 years earlier Sir John Carew had repaired the causeway walls and floodgates. The clay core dam faced with stone encloses an mill pond. The pond is about wide where the mill stands at the south end, narrowing to about at the north end, where there is a spillway. There are floodgates in the centre of the causeway dam. Building The present Carew Tidal Mill has two water wheels, one with the date of 1801, so was probably built around that time. The floodgates in the causeway