Wiwit taun 2000, Saint-Denis kerja sama kaliyan 7 "commune" sakitar (Aubervilliers, Villetaneuse, Pierrefitte-sur-Seine, Épinay-sur-Seine, L'Île-Saint-Denis (wiwit taun 2003), Stains (wiwit taun 2003) lan La Courneuve (wiwit taun 2005) ing Plaine Commune.