In the case of the Aceña Mill, there is some confusion derived from its own name. Traditionally, the "aceñas" are understood as the vertical wheels used in mills alternatively to the hydraulic wheels. We can still see some examples of medieval "aceñas", like those placed by the Guadalquivir bank when it passes by Cordova. It does not seem to be the case of the Aceña Mill, as it seems it has never worked by means of vertical wheel. On the contrary, medieval documents revealed was the generic word to refer to the mills, so almost all the references to the Guadaíra mills make reference to "aceñas" or water mills.
The first news on the Aceña Mill goes back to the distributions made by King Alfonso X in 1253. In these documents a mill that "In Moorish times was called Reha Luet" is mentioned, next to another mill "that was called Alcaxur grinding from a fountain". Cajul Mill, with many transformations from the 17th century, is still next to the Aceña Mill, being the original place name of this (Reha Luet) an adaptation to old Spanish of the Arab original name (Reha al-Wadi or the River's Mill).
Together with the Algarrobo Mill, the Aceña Mill is possibly one of those that preserve more late medieval elements. Although its origin may date back to the Andalusí period, it does not seem probable that previous elements to the 14th-15th centuries have subsisted, not only due to the consecutive transformations of the building but also due to the erosive action of the river, which has traditionally helped the original buildings no to last.
The mill is set up around a great square-plan tower with terrace roof and battlements. If we look downstream, there are two attached buildings where the grinding area is located. The weir, which drove the water into the buckets, ended up in a bridge that was connected to Guadaíra's left bank, allowing this way the water spill when the river level rose too much.