 The river basin was depopulated in the 8th century, according to Claudio Sánchez-Albornoz this was a deliberate act by Alfonso I of Asturias for the defence of his Kingdom, which led the area to be named Repoblación.The Douro "vinhateiro" (winegrowing), an area of the Douro Valley in Portugal long devoted to vineyards, has been designated by UNESCO as a World Heritage Site.Traditionally, the wine was taken downriver in flat-bottom boats called "rabelos," to be stored in barrels in cellars in Vila Nova de Gaia, just across the river from Porto.