Gruta do Janelão

Gruta do Janelão (MG-199) is a limestone cave located inside the Cavernas do Peruaçu National Park, in the municipality of Januária, Minas Gerais, Brazil. This cave is the largest in the valley, totaling 4,740 m of horizontal extension and elevation of 176m. Because it has several skylights letting the sun in, small forests that resemble Japanese gardens by the delicacy and harmony are formed everywhere, all by the banks of the Peruaçu River which runs through the Janelão grotto. It has the largest stalactite already registered measuring 28 meters long.

Cave data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).