Check out Altfinstermuenz and find out about its role in defending against attacks and invasions. This structure has witnessed some interesting history in its time.
You're spoiled for sightseeing choice when staying in Nauders. Altfinstermuenz is an ideal place to begin here, but there are lots of other fine places to experience. Reschen Pass, Bergkastel Cable Car, and Nauderberg Castle are near the history-filled fortress and will round out your day nicely.