Sécurité sociale tower, Brutalist office tower in Colombier district, Rennes, France

The Sécurité sociale Tower is a 19-storey office building in Rennes, 65.73 metres tall, designed by architect Paul Pothier and completed in 1965. Its pale beige concrete upper block is pierced by a grid of deeply recessed rectangular windows, while the ground level stands on rows of thick vertical pillars forming an open colonnade, with bands of dark glass between concrete floors above.

The Sécurité sociale Tower was built in 1965 to plans by architect and master builder Paul Pothier, as part of a larger urban development scheme for the Colombier district in central Rennes. It was designed from the outset to house the headquarters of the CPAM d'Ille-et-Vilaine, the departmental social security fund that still occupies it and gives the tower its name. Its 19 storeys of exposed concrete placed it among the tallest structures in the city and made it a marker of postwar rebuilding in the centre.

The tower symbolizes French administrative architecture from the 1960s and shapes the city center as the headquarters for social security services. Its robust concrete form reflects the era's vision of modern work and state presence in the urban landscape.

The building sits in a central location at the edge of the Colombier district, easily reached from the Esplanade Charles de Gaulle. Cinema screens operate at its base, and the nearby Le Liberté performance venue makes planning a visit straightforward.

At 66 metres to the roof, it is the tallest office building in Rennes, though the antenna of Le Mabilay reaches 83 metres. The top block, closed to the public, holds the tower's technical facilities. Across the street stand the Tour de l'Éperon and the cultural centre Les Champs Libres.