Port-Cros is a French island in the Mediterranean island group known as the Îles d'Hyères. It is part of the commune of Hyères, in the department of Var in the region of Provence-Alpes-Côte d'Azur. The island was donated to the French government with the promise that a national park, the Port-Cros National Park, would be created on the island. This was establis…Port-Cros is a French island in the Mediterranean island group known as the Îles d'Hyères. It is part of the commune of Hyères, in the department of Var in the region of Provence-Alpes-Côte d'Azur. The island was donated to the French government with the promise that a national park, the Port-Cros National Park, would be created on the island. This was established on 14 December 1963. The island is 4 km wide and its most elevated point is 199 m. It is 650 hectares.