Tarragona is that largest DO of Cataluña. The wine-growing region extends from the boundary with Penedés, but is hemmed in between the Mediterranean on one side and the Cordilleras Corstero Catalanas on the other. In the south-west the area abuts the vineyards of Terra Alta. There is the Priorato enclave renowned for its heavy red wines in the south-west of Tarragona. Trade in Tarragona is concentrated around the capital town of the same name and the small town of Reus. The small town of Falset is the centre of the Tarragona Classico trade in the west of the region.
Tarragona is subdivided into two sub-regions. The vineyards of El Camp de Tarragona (approx. 70% of the DO) are situated at a height varying between 131 feet (40 metres) near the coast and 639 feet (195 metres) at the foot of the Cordilleras. The soil chiefly consists of an upper layer of loam and chalk with a sub-layer of alluvial deposits. The south-western part, below the enclave of Priorato, from the small town of Falset to the vineyards of Terra Alta, is situated somewhat higher. Around Falset itself the vineyards reach up to 1,476 feet (450 metres), but in the west, in the Ebro valley their height is about 344 feet (105 metres). The soil of Comarca de Falset consists of underlying granite with a covering layer of loam and chalk around Falset and of alluvial deposits in the Ebro valley. The climate is predominantly Mediterranean but the higher vineyards are cooler in summer. The necessary rainfall comes mainly in the spring and autumn, while the summers are hot, dry, and of long duration.