Gruta do Centenário (English: Centenary grotto) (MG-1081), is a cave located in the municipality of Mariana, in the state of Minas Gerais, Brazil.

It is the largest and deepest quartzite cave in the world, and second in the country in terms of unevenness.

The beginnings of the Brazilian speleology in the eighteenth and nineteenth century mingle with the history of Caraça.

About this place, it is said that in 1922 the priests of the Caraça College had discovered at the Inficionado peak, which stands 2,068 metres (6,785 ft) above sea level, the Centenary grotto whose first speleological data appeared for the first time only in 1952 when a more technical survey took place resulting in a 3,790 horizontal projection (4,700 linear meters) and a vertical drop of 481 metres (1,578 ft) with several entrances, almost always in the form of pits.

[1][2] All ducts are narrow, ranging between 30 cm and 10 meters for passages that usually lead to the galleries.