The plains territory that stretches from the North Sea to the Meuse is home to one of the most dense and most varied collections of fortified towns in Europe. Still surrounded by their ramparts, these towns are more than just tourist and heritage attractions ; they now serve as an ideal experimental ground for contemporary urban evolution. Together with three organisations centred around the département du Nord, responsible for heading the project, nineteen fortified towns from northern France, Belgium and the southern Netherlands have led a programme of initiatives within the frame-work of « Septentrion », a European programme of cooperation assigned to study urban footprints and territorial development while respecting heritage and the environment. This collective work is intended for all those interested in the interaction between culture, heritage and territory, and in contemporary urban phenomena.