For an unique history lesson, visit the crumbling ruins of Nagashino Castle Ruins and imagine how it would have looked in its heyday.
You'll be spoiled for sightseeing choice when staying in Shinshiro. Nagashino Castle Ruins is an ideal place to begin here, but there are plenty of other worthy places to appreciate. Yuya Hot Spring, Horaiji Temple, and Shitaragahara History Museum are not far from the once-important structure and will top off your day nicely.