Moinho de Mare de Corroios

Moinho de Mare de Corroios is a tidal mill in the Tagus estuary.  A gate would allow the rising tide to push water into a pond.  Then at high tide, the gate was closed, and the receding waters were forced, Forced I tell you!, to retreat through the mill, turning mill stones for the grinding of grain.  This mill was in use for 6 centuries, one of many throughout the Tagus estuary, though now turned into a small museum.  You saw some pictures of mud from the Moinho; here are additional, more palatable shots of the Moinho. 

Exhibit illustrating the milling.  The hopper drops the grain down in between the grinding stones.  Because of the timing of the tides, being a miller was a pretty unpleasant business, requiring odd working hours, and numerous skills to keep the machinery working. 

Traffic sign directing you to the Moinho.  

The front of the mill.  The pond that captured the water was to the right.  Maintaining the pond required a lot of land, and protection by the local powers from other competing uses for the same area. 

Bus shelter ad for the Moinho.  It was in operation for 600 years.  Pretty good.  Lets see Intel match that sort of record for one of its chip making plants.  And probably with the same basic equipment here too, no upgrading for copper in the middle of your 500th year.  No Rambus technology here to license. 

The long side showing the openings for the water to escape turning that many grind stones.

The modern roof.  I've seen variations on this basic design on many structures around Portugal.