The Aquário Natural is the highlight of the Baía Bonita Ecological Reserve, set within close proximity to Bonito. When you first dip your feet into the crystal clear source of the Baía Bonita River, it truly feels as if you are entering a giant aquarium replete with over 30 varieties of fish and exotic underwater vegetation.
After suiting up and snorkeling in the spring, you can float down an 0.4-mile (600-meter) stretch of the river. The entire flotation (or flutuação) experience lasts 2.5 hours, while an extra add-on option includes a 90-minute visit to the Trilha dos Animais, an open-air refuge packed with regional wildlife whose denizens run the gamut from anteaters to anacondas.
The Reserva Ecológica Baía Bonita lies southeast of Bonito and can be reached by following the Estrada para Jardim for 4 miles (7 km). The reserve is open daily from 6am to 7pm, but tours must be booked in advance. A fee of R$120 per person includes wetsuit and snorkel gear rentals.