The Rio do Caldeirão ou Roncador is a tributary of the Santo Antônio River flowing through the spectacular quartzite landscapes of Chapada Diamantina National Park in the state of Bahia, northeastern Brazil. Originating in the elevated plateaus of the Serra do Espinhaço, the river carves through canyons and valleys before contributing to the broader Paraguaçu River basin, which spans approximately 54,877 km² and ultimately drains into Todos os Santos Bay. The river is celebrated for its crystal-clear waters, natural pools, and waterfalls such as Cachoeira do Roncador, and in its lower course it forms part of the Marimbus flooded plain — a remarkable wetland ecosystem covering roughly 4,800 hectares, often referred to as a "mini-Pantanal." This combination of free-flowing highland streams, scenic canyon reaches, and expansive lowland wetlands makes the Roncador one of the more ecologically rich and visually stunning waterways in northeastern Brazil.