A batán was a fulling mill where clothes were washed with a water powered machine in times gone by.
This is the only working example in Aragon. Originally from Lacort, at the time of the supposed construction of the Janovas reservoir it was removed and installed in Fiscal. The fulling machine was part of a hydraulic building which also housed a water powered saw and a flour mill.
You can still see it in action and admire the mechanism of this ingenious hydraulic invention, which in years gone by would have been one of many in Aragon.
Video by Eugenio Monesma about the Batán de Lacort: