The Pantanalis the world's largest wetland. This remote-feeling wilderness stretches for more than 80,000 square miles. It spills over from southwestern Brazil into both Paraguay and Bolivia. As with other wetlands, birds flock to the Pantanal. More than 1,000 species call the vast marshlands home. Rare mammals, like marsh deer, giant otters, anteaters and tapirs are found in the Pantanal. A large population of jaguars also thrives here. Since the Pantanal is difficult (and even dangerous) to traverse, going solo is unwise. Tours leave from several towns located near the wetlands. A majority of visitors opt for these guided excursions. Marshside towns such as Cuiaba (base for many tours of the northern sections of the Pantanal) and Campo Grande (base for southern sightseeing expeditions) are the most popular starting points.