In 1980, the town planners and elected officials of the new town of Cergy-Pontoise decided to grace the town with one of the greatest masterpieces of urban art. Today, the magical ribbon of the Axe majeur unfurls from the heights of Cergy-Pontoise towards Paris and crosses the Oise River, following the path imagined by town planners thirty years earlier. It is a total success: economic, political and technical difficulties have all been overcome by the faith of its creator, Dani Karavan, by the energy of the officials of the Agglomeration Community, and by the unwavering support of the Axe majeur association. Claude Mollard, one of the promoters of this colossal work, explains the aim of this saga, describes the players involved and looks back on the construction of the twelve stations that make up the Axis.