Which tropical wetland in Brazil is the world's largest?

The Pantanal is the world's largest tropical wetland, a vast seasonally flooded plain centered mainly in Brazil.

It lies chiefly in the Brazilian states of Mato Grosso and Mato Grosso do Sul, while extending into Bolivia and Paraguay. The wetland covers an area often estimated at roughly 140,000 to 195,000 square kilometers, depending on the boundary and definition used. During the rainy season, about 80 percent of its floodplains may be submerged.

This annual rise and fall of water creates a mosaic of rivers, lagoons, marshes, grasslands, forests, and dry woodland. It supports exceptional wildlife, including jaguars, giant otters, capybaras, caimans, hyacinth macaws, and hundreds of bird species. The Pantanal also acts as a major natural water-storage and flood-regulation system for central South America.

The Pantanal is sometimes confused with the Amazon because both are iconic Brazilian ecosystems. The Amazon is primarily a rainforest basin; the Pantanal is a flooded grassland and wetland. The Okavango Delta, Everglades, and Sundarbans are also globally important wetlands, but they are smaller or represent different wetland types.