The Brunella Fortress or Fortezza della Brunella
dominates Aulla, a large town in the Lunigiana region of northern Tuscany. Defending the territory at the confluence of the Aulla and Magra rivers to control access to the Via Franchigena, the fortress is one of the most effective military structures in the Lunigiana. While there was a castle here starting around the 13th or early 14th century, it was the 15th century when designers started to think of the new assaulting artillery that inflicted massive damage to castles starting around the 13th century, and most of what we see was built around the beginning of the 16th century.
The Brunella Fortress was privately owned until recently, and now there's a good natural history museum inside; if you're at all interested in this fascinating area you'll want to visit.
A good book about the region is A Tuscan Childhood by Kinta Beevor. When Kinta Beevor was five, her father, the painter Aubrey Waterfield, bought the Fortezza della Brunella, and Kinta lived there for years. Her only book, A Tuscan Childhood is a wonderful glimpse into the Lunigiana at the time.
The views from the castle are superb, as you'll see later in the tour.