Brazil has the world’s largest freshwater island, Ilha do Bananal.
Ilha do Bananal lies in the Araguaia River in central Brazil and covers approximately 20,000 square kilometres. It is separated from the mainland by two branches of the river and is generally regarded as the world’s largest river island, as well as the largest island surrounded by freshwater.
The island is located in the states of Tocantins and Mato Grosso. Much of it is protected through Indigenous territories and conservation areas. The landscape includes wetlands, forests, and grasslands, making it part of a transition zone between the Amazon, Cerrado, and Pantanal environments.
Ilha do Bananal is home to Indigenous peoples, including communities of the Karajá, Javaé, and Avá-Canoeiro. Its ecosystems support river dolphins, jaguars, giant otters, caimans, and many bird species. The island’s size varies somewhat by measurement and river conditions, but it is consistently recognized as the largest freshwater island. Marajó, near the Amazon’s mouth, is larger in area but is influenced by both river and ocean waters.