An aqueduct and bridge. Locals thought the Devil built it. Allegedly it is a "Roman" aqueduct and bridge. It appears to come from and go to nowhere but dirt paths. Similar to the Pont du Gard in France and other "Roman" and "Greek" aqueducts and aqueduct bridges.
Pont del Diable
Les Ferreres Aqueduct, Aqueduct of Tarragona, Arkeo Channel Aqueduct, Arkeo Channel Bridge, Devil's Bridge of Tarragona