The Maquiné Cave (Gruta de Maquiné) is one of the most accessible large cave systems in Brazil, around 110 km north of Belo Horizonte. It was the first commercial cave in the country — the Danish naturalist Peter Lund (later famous for his work on early human remains in the area) explored it in 1834 and opened it to visitors soon after.
Seven illuminated chambers are open on a guided tour of about an hour, with the usual range of stalactites, stalagmites, and limestone formations. The cave is permanently lit and the path is relatively easy. The surrounding park has a restaurant, swimming pool, and walking trails — a day trip's worth of activity.