Rioja Alavesa One of Spain's most famous wine regions is Rioja , a large area spreading down the valley of the Ebro, the country's longest river. Most of it forms its own province (La Rioja) but the northern part comes under the administration of Vitoria-Gasteiz and is known as Rioja Alavesa . It produces more concentrated wine than elsewhere but in smaller quantities due to the acidity of the…