 It takes its name from the River Guadiana, which flows through the region from east to west.The region was officially created in 1999 by combining the six sub-zones that up till then had produced Vino de la Tierra, a lower quality of wine on the Spanish quality scale.The DOP is divided into 6 sub-zones, of which Tierra de Barros is the largest, comprising 80% of the vines.