The Northern Fortress is a fortress owned by the Nohrian royal family. It is located northeast of the Nohrian capital of Windmire. After the Avatar was kidnapped from their Hoshidan family, Garon sent them to be raised there. Since he viewed the Avatar as weak, he refused to let them leave the fortress until they could prove that they were worthy to battle for him.
The Avatar was not always alone; their Nohrian siblings, Xander, Camilla, Leo and Elise often visited them during their spare time. Xander usually visited the Fortress to train the Avatar in combat so that they could leave and stay with the rest of their siblings in Windmire. During the Avatar's stay, their four retainers accompanied them; The veteran knight Gunter, the twin sister maids, the capable older sister Flora, and the clumsy younger sister Felicia, and their skilled butler Jakob. Lilith also lived in the Northern Fortress with the Avatar after they had unknowingly nursed her back to health.
Early on in the start of Fates, the Nohrian royal siblings visited the fortress. Xander tested the Avatar in combat and after being defeated, the crown prince told Garon that they were ready to fight. Garon, pleased with this outcome, allowed the Avatar to leave the fortress after staying there for so many years.
- According to the drama cd, the barrier in the fortress seems to strengthen the people who come inside it rather than protect the people that stay within it's walls.