Spain located on the Iberian Peninsula, has over 2.9 million acres planted—making it the most widely planted wine producing nation but it is the third largest producer of wine in the world, the largest being France followed by Italy. This is due, in part, to the very low yields and wide spacing of the old vines planted on the dry, infertile soil found in many Spanish wine regions. The country has an abundance of native grape varieties, with over 400 varieties planted throughout Spain though 80 percent of the country's wine production is from only 20 grapes—including the reds Tempranillo, Garnacha, and Monastrell; the whites Albariño from Galicia, Palomino, Airen, and Macabeo; and the three cava grapes Parellada, Xarel·lo, and Macabeo. Major Spanish wine regions include the Rioja and Ribera del Duero which are known for their Tempranillo production; Valdepeñas, drunk by Unamuno and Hemingway, known for high quality tempranillo at low prices; Jerez, the home of the fortified wine Sherry; Rías Baixas in the northwest region of Galicia that is known for its white wines made from Albariño and Catalonia which includes the Cava and still wine producing regions of the Penedès as well the Priorat region. Spanish wine laws created the Denominación de Origen (DO) system in 1932 and were later revised in 1970. The system shares many similarities with the hierarchical Appellation d'origine contrôlée (AOC) system of France, Portugal's Denominação de Origem Controlada (DOC) and Italy's Denominazione di origine controllata (DOC) system.