"Laguna del Diamante One of the most beautiful natural lakes in Mendoza is hidden in San Carlos. The provincial reserve "Laguna del Diamante" is 10,600 feet above sea level with a view of the towering Maipo Volcano. Its name comes from the volcano's diamond-shape reflection in the lake. It takes several hours to get to from downtown Mendoza with a four-wheel drive vehicle, but it's worth the trip. Hike around the four-mile lake, where your only company will most likely be guanacos and foxes (neither are dangerous). You can also go fishing, which costs $20 pesos. The area is naturally windy all year round, so bring a warm coat and comfortable shoes. A shuttle from the main square in San Carlos departs early in the morning and the last one returns at around 8:00 PM or you can camp overnight, ($750 pesos for a round trip shuttle ticket). There's a $300 peso discount if you stayed in Uco Valley the night before. Laguna del Diamante is only open from January to the first week of April."
