Mariana

The Portuguese and the British built railroads to transport the gold (and other minerals) in this area. Many of these railroads are since long abandoned, and Brazil now has a very small network of railroads. Brazil would have had significantly more railroads if the big police in the north wouldn't have interfered in order to establish a huge market for cars.
There is still an old train running from Ouro Preto to Mariana, which is a neighbouring town. The view from the train during this ride is spectacular.

I went into one of the old mines between Ouro Preto and Mariana. You enter the mine using an old small train car, which is connected to an engine with a loong rope. This slowly lowers you into the mine and afterwards pulls you up again. The mine is not active anymore and many of the tunnels have been filled with water. The water is very clear, since nothing can live there. Sometimes people go diving in the water and the visibility is supposed to be up to 50 m.

Entrance to the mine.

Entrance to the diving area.