Sardinia’s coastal towers were erected starting around 1570 at the behest of the Spanish Crown. The defense system was coordinated by the Royal Administration of Towers, established in 1581 by Philip II of Spain. The body remained operational until 1867, when a royal ordinance declared its abolition for military purposes. In reality, not all towers were suppressed, and some, passed under the jurisdiction of the Ministry of Finance, underwent substantial remodeling to adapt them for customs use. The final decommissioning of the towers did not occur until 1989. The Tower of San Miguel has a truncated cone shape, composed of granite and porphyry, it has two floors. These communicate by an internal staircase, while the terrace is accessible by a staircase in the lower classroom. Renovated in 2011, it is currently used as exhibition space.