Fotos

The tide mill at Alcochete is one of a number on the Sétubal Peninsula, along the south bank of the estuary of the River Tagus.

These large solid stone structures have great architectural value and are an important part of Portuguese heritage. A late 13th-century invention, they were the basis of a small flour-milling industry. This was particularly important in the making of ‘biscoitos’, a type of sea-biscuit used on ship voyages during the Portuguese Discovery period in the XV century.

A 2006 paper by M. Santos,Tide mills: the route of one forgotten heritage, draws attention to the present state of abandonment, and in some cases ruin, of these commanding structures and highlights the urgent need for their classification, conservation and renovation. http://library.witpress.com/pages/PaperInfo.asp?PaperID=15292.

A tide mill is a specialist type of water mill driven by tidal rise and fall. A dam with a sluice is created across a suitable tidal inlet, or a section of river estuary is made into a reservoir. As the tide comes in, it enters the mill pond through a one way gate, and this gate closes automatically when the tide begins to fall. When the tide is low enough, the stored water can be released to turn a water wheel. Tide mills are usually situated in river estuaries, away from the effects of waves but close enough to the sea to have a reasonable tidal range. These mills have existed since the Middle Ages, and some may go back to the Roman period. http://en.wikipedia.org/wiki/Tide_mill

Note: The image is rescued from another rescued old slide, so I hope you'll make allowances.