The area named after the river, with around 20,000 hectares of vineyards, was classified as DOC in 1990 and is located in the middle of the Beiras region in the north of Portugal. The viticulture goes back to ancient Greece. Especially in places where vineyards have existed for centuries, one finds numerous strange hollows and depressions in the rocks in the form of stone basins (Lagaretas). Probably grapes were pressed in these installations. This typical Portuguese method of crushing the grapes in the Lagares (stone troughs) is still practised today. The area is framed on three sides by granite mountains and thus protected from the Atlantic Ocean. About 80% of the land area consists of forests, only 5% is used for wine growing. Most of the vineyards are located on granite soils in the valleys of the three rivers Alva, Mondego and Dão. There are around 100,000 winegrowers, who often cultivate small plots of land of less than half a hectare. As a result, the vineyards are highly fragmented and often widely scattered in dense eucalyptus and pine forests.