dam in the Valencia region of eastern Spain, across the Monnegre River. It was erected late in the 16th century and is still in use. Its builders apparently made no stress analysis, but the dam's massiveness has kept it serviceable. It is 34 metres (110 feet) thick at the base, 28 metres (93 feet) thick at the middle, and 20 metres (65 feet) thick at the top.