The 17th-century Fort de l'Estissac on the coast of Port-Cros

Fort de l'Estissac is a former military work located at the northwest tip of the island of Port-Cros. Built between 1634 and 1640 on the orders of Richelieu, it was part of a defensive system designed to counter a threat to the coast. The fort's original design featured a circular cannon tower surrounded by a fortified enclosure with a ravelin to the northwest.

During the siege of Toulon in 1793, the tower was half-destroyed by the English. In 1812-1813, under the First Empire, Napoleon I ordered the restoration of the coast, leading to the reconstruction of the fort. The buildings on the fortified plateau were replaced by new barracks, and the remaining half-circle of the tower was completed with a square tower. This structure rises three levels high, with the top level being open-air and featuring two watchtowers.

The fort remained in service until its decommissioning in 1885. It was added to the inventory of historical monuments in 1947 and assigned to a park in 1997. Today, the fort is open to the public during the summer season, where visitors can view a presentation of the park and attend temporary exhibitions.

Sources: Wikipedia, OpenStreetMap, Wikidata, Wikimedia Commons