The municipal Archaeological Unit was created by the city of Saint-Denis in 1982, thus making permanent the action of the archaeologists who, had been excavating urban development zones to the north of the basilica since 1973. Today, eleven people work within the Unit, and contribute to its several missions:

Excavations: The Unit now intervenes across the whole communal territory, ensuring the archaeological management of town planning documents, and carrying out, each year, dozens of preventive archaeology operations. On the 1200 ha. of communal territory, 160 archaeological operations have been carried out.

Publications. Part of the team undertakes to conclude publication of 20 years of excavations, following the first volume of the series, l'Atlas historique de Saint-Denis (1996).

Public outreach. The Unit's program of socialization 'Archaeology, Territory and Citizenship' aims at providing reference marks for 'reading the city' and highlighting its heritage, source of local development. Teaching workshops and cultural action plans are designed for all publics.

Managment and heritage conservation. The Unit ensures the management and conservation of all finds, from their discovery, conservation and storage in controlled conditions.

Creation of databases. The Unit builds and maintains data bases concerning the territory. These include the data collected from previous and more recent excavations, a census of written and iconographic sources, specialized studies, university work as well as almost all of the archaeological material discovered on the communal territory, including nearly 40.000 special finds.

Since its creation the Archaeological Unit occupies buildings at 8 rue Franciade, an old nursery school which has been transformed, over the years into the "Maison de l'Archéologie".