Bierzo is a DO for wines located in the northwest of the province of León (Castile and León, Spain) and covers about 3,000 km².  Stylistically the wines are mid-way between the light fruity whites of Galicia to the west and big reds to the south.

It borders on the provinces of Ourense, Lugo and Asturias in the north and in the south on areas of La Montaña, la Cabrera and La Meseta, in Léon.

The area consists of numerous small valleys in the mountainous part (Alto Bierzo) and of a wide, flat plain (Bajo Bierzo). The majority of vines are planted at 500-600m along the valey of the river Sil and its tributaries on slopes and terraces. The soils are alluvial with traces of iron at lower levels, slate higher up.