Formosa do Rio Preto is the westernmost and largest (by area) city in the Brazilian state of Bahia. It is also the largest in all Northeastern Brazil. The municipality contains part of the 707079 ha Serra Geral do Tocantins Ecological Station, a strictly protected conservation unit created in 2001 to preserve an area of cerrado. It also contains part of the 724324 ha Nascentes do Rio Parnaíba National Park, created in 2002.