On the defensive walls built by the Etruscan from the sixth to the second century to C., there are small cavities (centimeter sized), which can be interpreted as micro-tafoni of natural origin. The observations carried out on these walls built with blocks of “Macigno” of Oligocene age sandstone highlighted a significant relationship between the depth of the tafoni and their position expressed in degrees on the horizontal plane of the artifact. It therefore appears that due to the insolation and the resulting thermal excursion, the formation and deepening of the tafoni occurred more on the Southern and surfaces exposed to than on the others.

Keywords: Tafoni, Corsica, Alveolar weathering, Etruscan Walls, Oligocene sandstone (Macigno).