Location from harry-potter-deathly-hallows by
The castle that became a fortress -- a thousand-year-old school now occupied by Death Eater professors and defended to the last stone by the students, teachers, and ghosts who call it home.
Hogwarts under the Carrow regime is a school in occupied territory. Amycus Carrow teaches Dark Arts -- not Defense Against, just Dark -- and forces students to practice the Cruciatus Curse on each other. Alecto Carrow teaches Muggle Studies as anti-Muggle propaganda. Snape sits in the Headmaster's chair and everyone believes he is the enemy. Neville runs a resistance from the Room of Requirement. When the battle comes, the castle fights back. McGonagall animates the suits of armor. Sprout throws Venomous Tentacula. Flitwick uses his dueling championship skills. The passage from the Hog's Head fills with reinforcements. The castle's ancient enchantments, built up over a millennium by the greatest witches and wizards in history, hold against Voldemort's forces until dawn. The Battle of Hogwarts is fought in corridors where students once walked to class, in the Great Hall where they ate breakfast, on the grounds where they played Quidditch. The castle is damaged but not destroyed. It endures. It always endures.
An immense medieval castle of towers and turrets rising from a Highland promontory. Moving staircases, talking portraits, torches that light themselves at dusk. Now darker than before -- the Carrows patrol the corridors, students whisper instead of shout, and Dumbledore's Army marks appear on the walls overnight. The suits of armor stand ready to be animated. The castle itself seems to be waiting.
Also known as: Hogwarts, Hogwarts School, the castle, the school