This 558-sq-km reserve, created in 1999, lies 150km down the Rio Madeira from Porto Velho and is accessible only by river. It’s Rondônia’s largest fish-spawning ground (pirarucú and aruanã are among the species breeding here) and is renowned for its abundant bird life. Plans to open the reserve to tourism have been delayed by several years, as IBAMA completes required environmental studies. Contact IBAMA in Porto Velho to check the progress.