What can be done in the Gran Chaco of Paraguay? Here is what I found on the Gran Chaco, The Gran Chaco is a sparsely populated, hot and semi-arid lowland natural region of the Río de la Plata basin, divided among western Bolivia, Paraguay, northern Argentina and a portion of the Brazilian states of Mato Grosso and Mato Grosso do Sul, where it is connected with the Pantanal region. This land is sometimes called the Chaco Plain. Wiki.