This is a two-faced fireplace, from the shot we can see only the oxidized iron side.
Placed in a bearing wall, it allows the maximum output, due to its central position inside the house, fire irrigates from two sides. The frame, visible from the picture, is made of iron treated with acids in order to create a more homogeneous oxidization than the natural one, then fixed by using a proper treatment. It appears as a little furnace, the central and dynamic engine of the house. Fire can be seen from every corner of the building, thanks to special perspectives created by holes and transparencies, even in ceilings.