Gazteluondo tide mill
The original construction dated from the post-medieval period, 16th century. Taking advantage of the high tide,the mill collected water in a reservoir. Then, when the sea level dropped, the water was discharged.
This mill was originally built during the late Middle Ages, in 1506. This is the oldest tide mill in Bizkaia and was known as the “Gazteluondo Mill”, as it was located under a small castle or fortress. All that remains are the machinery and millstones, since the building could not be preserved when the mill had to be moved to build the bridge and road.
The mill worked thanks to the rising and receding movement of the tides. The rising tide would fill the reservoir and when the tide ebbed, the reservoir would empty into the estuary, flowing under the milling mechanism. The force of the water moved a water wheel that rotated the top millstone over the fixed stone. Thus, the grain introduced through the top would be milled into flour by the movement of the millstone and fall into the corresponding container.
