Museum of el aceite al aire libre Monument · Maleján, Campo de Borja, Zaragoza Image of Maleján, not of the place itself. Maleján displays in its streets oil-mill machinery of the beginning of the twentieth century: screw presses, millstones, pressing mats and tanks recovered from the old mills of the comarca. The route explains how oil was obtained before mechanisation. Photo: Ecelan (CC BY-SA 4.0) What to see and do in Maleján