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The Gran Chaco

The Gran Chaco is a vast alluvial lowland, stretching north from Santa Fe and Córdoba provinces, across the entirety of Chaco and Formosa, and into Paraguay, Bolivia and Brazil. The western side, known as the Chaco Seco (Dry Chaco), has been dubbed the Impenetrable, due to its severe lack of water across an endless plain of thorn scrub. The eastern side is attractively fertile, and an important wildlife habitat.

Crossing the Gran Chaco from Formosa to Salta along the northern RN 81 is an interesting option on mostly decent paved road.