Château de Fos-sur-Mer, Medieval castle on a hill in Fos-sur-Mer, France.

Chateau de Fos-sur-Mer is a medieval fortress sitting atop a hill 32 meters (105 feet) above the surrounding terrain and overlooking the bay. The complex features a defensive curtain wall with a walkway, two sturdy towers, and two monumental gates that worked together as a system for watching the coast.

The first written record of the castrum de l'Hauture and its chapel dates to 923, when the site was built to guard against Moorish invasions and to watch maritime trade. It was enlarged and modernised in the 13th century. From that century until the Revolution, the Porcelet family ruled the fief and still gives its coat of arms to the commune.

The castle is also called château de l'Hauture, after the hill it stands on. The Porcelet family ruled the fief from the 13th century until the Revolution, and their coat of arms is still that of the commune of Fos-sur-Mer. The chapel remains in use for baptisms and weddings.

The site is fairly easy to reach on foot since the climb is not steep and follows a main path up the hill. Visitors should wear comfortable shoes and be prepared for open sun, especially on warm days.

Archaeological digs have uncovered more than a hundred burial sites, numerous storage silos, and ancient dwellings carved into the hillside from the medieval period. These discoveries reveal that the fortress served as both a military post and a residential community for ordinary people.