The Castilla y Leon region of Spain is located in the northwestern part of the country and is known for its high altitude vineyards, diverse terroir, and extreme climate. The region is divided into several sub-regions, including Ribera del Duero, Toro, and Rueda, each with its unique styles of wine.

Ribera del Duero is one of the most famous wine regions in Spain, known for its powerful, full-bodied red wines made from the Tempranillo grape variety. The high altitude vineyards, extreme climate, and limestone soils of the region create ideal conditions for growing Tempranillo grapes with intense flavors of black fruit, spice, and earthy notes. The region came to fame by the growth of Vega Sicilia, which was planted in 1864, and can best be compared to Cabernet Sauvignon from the Napa Valley thanks to those rich and bold flavors, but tend to be more refined and Old World in style, more balance and less overpowering oak.

Toro is another red wine-focused sub-region of Castilla y Leon, known for its bold and full-bodied wines made from the Tinta de Toro grape variety, a local clone of the Tempranillo grape. The vineyards of Toro are located at high elevations, where the hot and dry climate results in grapes with concentrated flavors and high tannins.

Rueda is a white wine-focused sub-region of Castilla y Leon, known for its refreshing and aromatic white wines made from the Verdejo grape variety. The sandy soils and cool climate of the region create ideal conditions for growing Verdejo grapes with zesty flavors of citrus and tropical fruit.