Dão is a Portuguese wine region situated in the Região Demarcada do Dão with the Dão-Lafões sub region of the Centro, Portugal. It is one of the oldest established wine regions in Portugal. Dão wine is produced in a mountainous region with a temperate climate, in the area of the Rio Mondego and Dão rivers in the north central region of Portugal. The region became a Denominação de Origem Controlada (DOC) appellation in 1990. The Dão region is the origin of the Touriga Nacional vine that is the principal component of port wine. Climate and geography The wine region is located primarily on a plateau that is sheltered on three sides by the granite mountain ranges of Serra da Estrela, Serra do Caramulo and Serra da Nave. This helps the area maintain its temperate climate away from the effects of the nearby Atlantic Ocean. The region experiences abundant rainfall in the winter months and long, warm dry summers leading up to harvest. The region's vineyards are planted on sandy well-drained soil on top of granite rock. History The first efforts to have the Dão region recognized as a separate and unique wine region came mainly from the aristocrat and winemaker João de Sacadura Botte Côrte-Real. Considered to be "the most enlightened viticulturist of his generation", he modernized the processes of winemaking and raised the standards of the wine produced in the region. He had many wine estates, in both Portugal and Spain, but the most celebrated were his Quinta da Aguieira and his wife's Quinta da Bica. The Dão was first officially recognized as a Região Demarcada in 1908. In the 1940s, to improve the quality of the wine from the region and promote some sort of national identity, the government of Prime Minister António de Oliveira Salazar instituted new regulations establishing the mandatory use of co-operatives in the region. These co-operatives would have exclusive privilege to the grapes grown in the region and were charged with making the wine that would be sold to private merchants. Despite its intent, the regulations had an adverse effect on the Dão wine region by promoting stagnation due to lack of competition, with some co-operative firms releasing inferior quality wine and even practicing un-hygienic winemaking. In 1979, Portugal's application to the European Union prompted authorities to overturn these rules, as the EU discouraged monopolistic practices in the wine industry. Viticulture and wines The