Replaton is one of the three forts near Modane. They had to close the valley of the river Arc. However Replaton also had a second task: the defense of the railway tunnel to Italy. It was built between 1886 and 1891, but it has the appearance of a medieval castle. Here you can see the front with several casemates for the guns that fired at the tunnel. The armament of the fort consisted of two 155 mm guns, four 95 mm coastal guns and five 95 mm field guns.