The Embalse de Cruz del Eje, also known as the Dique Arturo Umberto Illia, sits in the northwest of Córdoba province at approximately 30°46'S, 64°44'W, at an elevation of 530 meters above sea level. The reservoir was originally completed in 1943 and extensively remodeled in 1980, when its dam wall became the longest multiple-arch buttress dam in South America at 3.2 kilometers. The dam stands 40 meters high and impounds the Río Cruz del Eje, which is fed by several sierra tributaries including the Quilpo and San Marcos rivers before eventually draining toward the Salinas Grandes. The reservoir covers approximately 10.9 square kilometers (roughly 1,000 hectares) with a total storage capacity of around 112–123 cubic hectometers.

For paddlers, the reservoir offers a substantial open-water environment well suited to kayaking and motorized boat excursions. Organized kayak events have been held on the lake, including both daytime and evening sessions, with safety briefings on vessel regulations forming part of those programs. Boat rental clubs operate in the area, providing options for those without their own equipment. The dam wall itself extends for 3 kilometers along one edge of the reservoir, creating a distinctive boundary to paddling routes on that side.

Access to the reservoir is via Ruta Nacional 38 and provincial road A185, reaching the area known as Cuenca del Sol, located approximately 7 kilometers from the town of Cruz del Eje and about 140 kilometers from the provincial capital. The surrounding landscape is characterized by sierra terrain with native flora and fauna, and walking trails exist in the vicinity for those combining paddling with land-based exploration.

The reservoir supports populations of pejerrey, carpa, tararira, dientudo, boga, and dorado, making fishing activity common on the water. Anglers are frequently present along the dam wall and in quieter coves, which is worth factoring into route planning. An annual Festival Regional del Pejerrey takes place in February, drawing additional visitors to the area. The Círculo de Oficiales del Dique Arturo U. Illia, located on the lake shore, serves as a reference point for organized paddling events and inquiries can be directed to the local tourism office at 3549-536427.