There is a question as to the location of this city between here and Vermand. The current state of knowledge indicates that this was the Augustian period town, but that it was abandoned in favor of Vermand in the late 3rd century. The site of Vemand, with its precipitous hill, is cetainly more in keeping with the site of a typical Oppidum.
http://fr.wikipedia.org/wiki/Vermand
http://fr.wikipedia.org/wiki/Saint-Quentin