"Setantrillon", as this interstate association is called, is translated from French as "north". These cities are located on the shores of the North Sea, in the northwestern part of Europe. The association includes from France - Lille, Saint-Omer, Cambrai, Maubeuge, Er-sur-la-Lis, Gravelines, Condé-sur-Esco and several smaller cities, from Belgium - Charleroi, Ypres and Lanaken, the Netherlands - Maastricht and Herzogenbusch.
All of them have preserved fortifications dating back to the 15th - 18th centuries. With the support of the EU's North-West Europe program, the cities of Cetantrillon have been preparing for the application to UNESCO for four years, restoring and reconstructing historical and architectural heritage sites on their territory. Along with the preservation of monuments, the function of the association is also to develop aspects of resource conservation and preservation of environmental cleanliness in these settlements, the motto of this association is “fortified cities -“green”cities : the municipal authorities of the cities participating in the program pay close attention not only to past achievements but also on future successes.
The only problem that Cetantrillon has so far faced is the refusal of the French branch of UNESCO to include the fortified city of Vauban in the application, but the organization's leadership plans to appeal this decision.
