If you want to visit the tunnels and see the guns which protected Switzerland in WW2, you can. It is all still there to see. Visit https://forteresse-st-maurice.ch/ to find out more.
Saint-Maurice Fortress, where Philippe is stationed, is one of the three main fortification complexes comprising the Swiss National Redoubt, formed to protect the Alps from invasion. The fortress is a series of fortifications set into the mountains on either side of the valley, including Fort de Dailly,