Post-coastal towers or rural fortress towers, built in the sixteenth century on the Mediterranean coast, had the mission of protecting the population and enhancing the repopulation of these areas, heavily punished by incursions by berber pirates. The Negro Tower or Arráez Tower, in El Algar-Cartagena (Region of Murcia, Spain), is one of those post-coastal lookout towers and was built in 1585. It is shaped like a truncated pyramid, square plan and a height of about 14,00 m. Originally, it had three floors and a terrace.
The contribution aims to present the path of knowledge on the external surfaces of the Courtyard of the Cavallerizza and the Castle of San Giorgio in Palazzo Ducale in Mantua, the subject of an upcoming conservation project. In particular, the results emerged through the autopsy and stratigraphic survey of areas selected by sample, relating to the technique of execution and the constituent materials of the finishes.