Rioja is a wine region in Spain that is known for producing some of the country's best wines. The region is divided into three sub-regions: Rioja Alta, Rioja Alavesa, and Rioja Oriental. The wines produced here are made from primarily Tempranillo grapes, along with Garnacha, Graciano, and Mazuelo. Rioja wines are aged for varying lengths of time in oak barrels, which imparts them with unique flavours and aromas. Some of the most popular types of Rioja wines include Crianza, Reserva, and Gran Reserva. These wines are versatile and pair well with a variety of foods, making them a favourite among wine enthusiasts.