The Colchagua Valley lies to the south of Santiago and makes up a major part of the Central Valley. Colchagua Valley is renowned for producing great quality wines, and it is a name associated with several prestigious Chilean wines. As with most areas of Chile, the cooler temperatures provided by the ocean varies across the Colchagua Valley. Generally, white grape varieties are found in the cooler climates, while red varieties thrive in drier, warmer climates. Therefore, there is a dominance of Cabernet Sauvignon, Carmenere, Malbec and Merlot in the warmer east with Chardonnay and Sauvignon Blanc in the cooler west. The Tinguiririca River is a key feature in Colchagua, as it flows along the northern edge of the region, and through the town on Santa Cruz, around which many wineries are based.