Wondering about the name? The Traverse du Frioul got its name from the Frioul archipelago near Marseille. The provençal word Frieu means a maritime passage between two islands. It now refers to the sea separating Pomègues and Ratonneau. By extension, it gave its name to all the islands.
The Frioul islands consist of four islands. These are Pomègues, Ratonneau, If, and Tiboulen. Pomègues and Ratonneau are connected by the Berry Dyke. Louis XVIII built it in 1822. It is named in honor of the Duke of Berry. He was assassinated by Louis Pierre Louvel in 1820. This dyke transformed a mooring area into a real port. Romans had used it.
These islands form one of Marseille’s 111 districts. They belong to the 7th arrondissement. The Frioul islands played a key role in Marseille’s defense. Each peak has a military fort. Batteries, trenches, and observation posts dot the archipelago. Henri IV built a fort on Ratonneau. Later, fortifications extended under Louis XIV by Vauban. Napoleon also added military structures.
The army built the Pomègues semaphore in 1902. It watched over the harbor for 90 years. During World War I, observation balloons were stationed here. The German occupation modified island fortifications during World War II. They built new concrete batteries. Allies heavily bombed the fortified archipelago. This was to destroy defenses blocking access to Marseille.
Until 1975, the Frioul islands remained military land. Gaston Defferre, the mayor, got permission to create a marina. It included 450 homes and some shops. A maritime shuttle service was created for residents. The Defense Ministry ceded the remaining islands to Marseille starting in 1995.
During the 18th-century plague, Ratonneau and Pomègues served as quarantine sites. In the 1920s, authorities set up a health sorting center for Armenian refugees. Alsatians, Lorrainers, and Germans were interned on the islands during World War I.
The Frioul islands are a car-free zone. There is a marina with over 600 berths. About one hundred residents live on these islands year-round. There are nearly 650 square meters of shared gardens. A Léo Lagrange holiday center is located here. There is also a marine fire station. A bio marine farm operates in Pomègues’ old quarantine port. Public services are limited. Residents go to the city for police, schools, and doctors.
The Frioul islands’ geology dates back to the Urgonian period. Like the Calanques, it features white limestone cliffs. Military activity left debris and metal pollution. The islands have endemic coastal species. There are also some rare and protected species.
Birdlife dominates the fauna. Some seabirds are rare and protected. The Frioul islands are a breeding ground for many gulls. Introduced species like rabbits and black rats thrive. Sicilian lizards live in the walls. The European leaf-toed gecko is also present.
The archipelago is dry with less rainfall than Marseille. Its low relief contributes to this. Combined with strong winds, this creates rare vegetation. Thirteen species are protected nationally or regionally.
The Frioul islands are part of the Natura 2000 network. This balances human activities and nature protection. The Calanques National Park is considering visitor quotas.