Flowing through the heart of the Pantanal — the world's largest tropical wetland — the Rio São Lourenço is a tributary of the Paraguay River and one of the most celebrated sport fishing destinations in Mato Grosso, Brazil. Rising in the southern reaches of Mato Grosso state (where it is sometimes known as the Pingara River in its upper course), the river flows westward into the Encontro das Águas State Park, where it meets the Cuiabá River, then continues southwest along the border between Mato Grosso and Mato Grosso do Sul before emptying into the Paraguay River. Its crystal-clear waters, lush riparian vegetation, and diverse aquatic habitats — including backwaters, deep pools, current areas, and flooded forests — make it one of the most productive and visually stunning fisheries in all of South America. The river is widely regarded as part of the "fishiest region in the entire Pantanal," a vast alluvial plain shared by Brazil, Bolivia, and Paraguay that supports an extraordinary diversity of freshwater fish.