Over millions of years, the rushing waters of the Rio São Miguel have sculpted rock formations in the landscape of Vale da Lua, a gorgeous valley whose blackish stone outcrops contrast with the green cerrado vegetation. In the river, a metaconglomerate of rocks containing quartz, sand and clay reflect a rainbow of colors; pools of chilly emerald waters give relief from the baking heat.
Vale da Lua is outside the national park and subject to flash floods during the rainy season. There's a signed turnoff 5km from São Jorge on the way to Alto Paraiso, then it's 3.5km down a dirt road to the car park. From here, it's an easy stroll of under 1km to the river, but take sunscreen and water with you.