This volume is dedicated to the study of the field-fortifications on the Finestre and Fattières hills located in Piedmont on the Italian Occidental Alps; being the unique easily passable transit between the Chisone valley and the fortress of Susa, they had a special strategic meaning and importance. The first part of the book focuses on the historical documentary study of the fortification existence phases from the first half of the XVII century up to 1799 and on the change from French dominion to the House of Savoy control. The second part pertains to the archeological researches carried out between 2007 and 2012 on the sites where the remains of the field-buildings are still evident. Great attention is dedicated to territorial recognition added to the intensified study of the most important defensive components. The essay is supplied with archeological remarks and photographic material. They aim at presenting the real extension of the whole defensive system as well as the still visible consistency of the archeological remains.