Scarce Spanish sea chart of the Rio de la Plata

A detailed seachart of the Rio la la Plata, separating Uruguay from Argentina, marking Buenos Aires and Montevideo. Lighthouses are marked in colour. At the time of publication the Paraguayan War (1864-70) was being fought between an alliance of Brazil, Argentina and Uruguay, and Paraguay, a power-struggle for control of the Rio de la Plata basin. Spanish charts such as this were regarded as state secrets, so rarely come on the market.