This large area of north west Spain roughly occupies the Spanish part of the Duero river basin. This is the northern part of the Mesata Central - a dry, high and arid plateau in the middle of the peninsula. Winters are long and cold and summers are short and hot and it is generally very dry. The Douro river provides a essential water supply for irrigation. Vines must put down deep roots in these conditions to draw nutrients and minerals from the soil. This imparts a great deal of character to these wines.