Upstream the Guadaíra, Alcalá's miller bank starts with the Hundido Mill, placed on a bend of the river where environmental values have priority on the present building, which is very affected by contemporary hydraulic facilities. Before arriving to Aceña Mill, we find the Marchenilla Brook, which flows into the Guadaíra by its right side. This course, very decreased at the present time, connected the area of the Marchenilla Castle to Aceña Mill historically, allowing the establishment of several brook mills moved by hydraulic power, channelled off through channels or reservoirs: Pared Alta, Granadillo, El Hornillo, San José and La Boca. Most of these mills were started during the Late Middle Ages (14th-15th centuries), although the buildings we still can see today are mostly the result of transformations and re-constructions of the Modern Age (16th-18th centuries).
Nowadays, all Marchenilla's mills are placed inside private properties, being even some of them inhabited, which has enabled in several cases its conservation up to our days.
Downstream La Tapada, the miller landscape has river mills (El Arrabal, Realaje, Pelay Correa and Cerrajas Mills) and brook mills (like the ones of the Zacatín, very transformed and in part missing). Today, most of the river mills downstream Alcalá can be visited from the Green Corridor recently fit out between Alcalá de Guadaíra and Pablo Olavide University (UPO).