[ree-BEHR-ah del gwah-dee-AH-nah] do zone located in the Extremadura region in western Spain on the Portuguese border. In 1998, six vino de la tierra areas were combined to form this DO-Cañamero, Montánchez, Ribera Alta, Ribera Baja, Matanegra, and Tierra de Barros (the best known of the six). This zone takes its name from the Guadiana River, which flows through the area and eventually into Portugal. There is a broad assortment of grapes grown throughout the region. White varieties include Alarije, Borba, Cayetana Blanca, Pardina, Viura (macabeo), chardonnay, Montúa, Malvar, parellada, pedro ximénez, and verdejo. Red varieties include Garnacha (grenache), tempranillo, Bobal, cabernet sauvignon, graciano, Mazuela (cari­g­nan), merlot, Monastrell (mourvèdre), and syrah. A number of these grapes are of lesser quality, and a movement is underway to reduce their use and focus on the higher-quality varieties.