Ardres is a commune in the Pas-de-Calais department in northern France. Ardres is located 10.1 mi by rail S.S.E. of Calais, with which it is also …Ardres is a commune in the Pas-de-Calais department in northern France. Ardres is located 10.1 mi by rail S.S.E. of Calais, with which it is also connected by a canal. It is one of three towns that make up Les Trois Pays, or "Three Countries", the other two being Guînes and Licques.