Gruta das Areias is a complex of caverns located in the region of Lajeado, in the municipality of Iporanga, São Paulo, Brazil. It is therefore part of the Areias System, located in the southwestern part of the carbonatic area Lajeado-Bombas, on the right bank of the Betari river, in the municipality of Iporanga, southeast of the state.[1] It comprises the caves Ressurgência das Areias (SP-016), the 5.565 meter-long cave Areias de Cima (SP-018) and the Areias de Baixo (SP-019) cave, also popularly called Areias I and II.[2] It is also part of the so-called Açungui group of caverns formed between the Mesoproterozoic and Neoproterozoic, between 1.6 billion and 539 million years ago.[1]