From the J4 to the fort Saint-Jean

Set off to explore the contemporary architecture of the J4 and the historical Fort Saint-Jean on this free tour.

Visitors All ages
Length 45 minutes


J4: Contemporary Architecture in “Super Concrete”

Since it opened in 2013, the building designed by Rudy Ricciotti (in association with Roland Carta) is world-renowned for its architecture combining technical prowess and visual power. An open tour through the Mucem, along the latticework!

Outside ramps

Start on the ground floor, in the entrance hall of the J4. From there, two outdoor ramps lead to the rooftop terrace, inviting visitors to experience a fascinating upward walk with a view of the Fort Saint-Jean and the horizon. Move from one ramp to the other via the outdoor stairs!

Branching posts

When crossing, you will see immense pillars in the form of “chicken bones”: the J4 is held up by 309 branching posts surrounding its exhibition rooms so that the middle of the building has no load-bearing functions. They are made of UHPFRC (ultra-high performance fibre-reinforced concrete), a next-generation material that is as supple as it is resistant.


You are now approaching the famous lattice, slender concrete lacework that delicately wraps around the J4 building. It too is made of UHPFRC and allows light, air and the scent of iodine to filter through, whilst also serving as a windbreak. Architectural prowess plus visual signature: the lattice is the real symbol of the Mucem.

J4 footbridge

Ahead is the J4’s rooftop terrace, from which an aerial footbridge stretches out to the Fort Saint-Jean. Here you will find neither arches nor stays, but rather a simple line of black concrete suspended 19 metres high. A technical challenge achieved through the extraordinary properties of that “super concrete”, UHPFRC.


Fort Saint-Jean: Stroll with a View of Eight Centuries of History

Change of scenery: as you exit the footbridge, the contemporary architecture of the J4 will give way to the pink stone of the Fort Saint-Jean, whose upper section was erected in the 17th century (during the reign of Louis XIV) by Vauban and Clerville, although its origins are much, much older. Between towers, ramparts, vaulted rooms, gardens and panoramic views, a tour of the fort will take you on a journey through the history of Marseille.

From Fanal Tower toward the Chemin de Ronde (1)

The footbridge from the J4 lets out on a vast open-air esplanade, the fort’s Place d’Armes. To the right is Fanal Tower (or Round Tower), built in 1644 at the request of the ship-owners of Marseille, most likely to guide in ships arriving by night or in the fog. Pause a moment on its terrace with a view of the open sea before continuing your tour along the ramparts of the Chemin de Ronde (20 m above sea level) toward the Officers’ Gallery.

Officers’ Gallery

A portion of the Royal Guard was housed here during the 17th and 18th centuries.

Cour de la Commande

In the lower part of the fort, ruins are dotted around the Cour de la Commande, reminding us that the site was occupied by the Knights Hospitaller of St. John of Jerusalem beginning in the 12th century. In fact, the chapel was built during the Crusades, when a St John’s Commandery stood here. It had its own hospital, whose great room was pierced when the fort was constructed to create a cannon rise.

From the Cour de la Commande, the cannon rise will lead you toward the top of the fort. From here, you have two choices:

Toward the Chemin de Ronde (2) and King René Tower

Head left: you’re free to lose yourself in the village and follow the ramparts of the Chemin de Ronde (this time on the city side) to King René Tower (which gets its name from King René of Anjou, Count of Provence), which was erected in the 15th century to control access to the port. You will have access to its terrace with a spectacular view of the Old Port, where up to 12 cannons were in place in the past.

Toward the Panier footbridge

Head right: the cannon rise leads to the Royal Gate, for a long time the main entrance to the fort (protected by a drawbridge). Today, it is still one of the entrances to the Mucem: a 70 metre long footbridge (in UHPFRC) connecting the fort to the city via the Panier district, the oldest in Marseille.