Embalse Río Hondo is a sprawling reservoir nestled on the border between the provinces of Santiago del Estero and Tucumán in northwestern Argentina, with the lake's surface divided nearly equally between the two provinces. Created by the Dique Frontal dam, inaugurated on September 27, 1967, the reservoir covers approximately 33,000 hectares (330 square kilometers) of water surface, making it one of the largest reservoirs in the region. Located just 5 kilometers from the center of the resort town of Termas de Río Hondo and roughly 87 kilometers from Tucumán, the embalse is fed by rivers descending from the Aconquija Mountains and serves multiple purposes including flood control, irrigation, hydroelectric generation, and sport fishing. The warm, mild climate — with an average temperature of 20°C — and the reservoir's rich fish population have made it a premier destination for sport fishing and nautical activities in northwestern Argentina. The ideal travel window for visiting the area runs from March through November.