The Pantanal is the world's largest tropical wetland, stretching across roughly 200,000 square kilometres in western Brazil (mainly Mato Grosso and Mato Grosso do Sul) and spilling into Bolivia, Paraguay and Argentina. UNESCO recognises it as a World Heritage Site and Biosphere Reserve. While the Amazon gets more attention, wildlife watchers consistently rate the Pantanal as the better destination: the open savanna-wetland landscape means animals are far easier to spot than in dense rainforest.
The wetland floods seasonally. From December to March, rains transform the plain into a vast inland sea — the historic name was the "Xaraés Ocean". The floodwaters concentrate fish and attract extraordinary densities of birds, caimans and capybaras. As waters recede between April and June, wildlife gathers around remaining pools and channels, making this the prime season for wildlife photography. August to October is the classic fishing season, when migratory fish ("lufada") return to the rivers.
The best base towns are Aquidauana, Corumbá, Coxim, Miranda and Porto Murtinho — traditional cattle-ranching communities ("pantaneiros") that have embraced eco-tourism. From these towns you can arrange boat trips, horse rides, night safaris to spot caiman eyes glowing in the dark, and guided birdwatching. The Caiman Ecological Refuge near Miranda is among the best-regarded operations for wildlife encounters.
Near the southern Pantanal, the town of Bonito is a separate but complementary destination: crystal-clear rivers fed by limestone springs allow snorkelling among shoals of fish, and the Blue Lake Cave is one of Brazil's geological wonders.