Most of Argentina's wine-making areas are in one small strip of high, almost desert land that fits best in the continental climate category. Most of the vineyards are located about 980-1250 feet above sea level, which lets them take advantage of a lot of daytime sunlight, and cooler nighttime temperatures. There is almost no rainfall in this area, so Argentinians use irrgigation systems that get water from runoff from the Andes mountains. The soil is mostly sandy, with clay or loam over a bedrock of limestone, gravel, and clay.