The Site is located on the Paraná River, on the border of the states of Paraná and Mato Grosso do Sul, near the border with Paraguay. It is composed of approximately 180 islands, as well as river banks, natural ponds and freshwater marshes. The National Park protects two types of environment that are now rare and degraded in the Brazilian Mid-South: riparian forests and floodplains. Besides the scenic beauty, these areas are important breeding and feeding places for several species of fish. It also hosts various endangered species, including the marsh deer Blastocerus dichotomus, symbol of the National Park, the brown howler monkey Alouatta fusca and the Southeastern four-eyed opossum Philander frenata, which is endemic to the Atlantic Forest. Fires, hunting and the introduction of alien species all present threats to the Site.