Alnwick Castle is the second largest inhabited castle in England, after Windsor, and it has been the home of the Percy family — Dukes of Northumberland — since 1309. The outer walls and towers are medieval and formidably intact; the interior was remodelled in the nineteenth century by Anthony Salvin and then decorated by the 4th Duke of Northumberland in an Italian Renaissance style, so the rooms are unexpectedly opulent for a north country fortress. The state rooms are open to the public and contain paintings by Titian, Canaletto, and Turner.
The castle's fame has grown enormously since it appeared as the exterior of Hogwarts in the Harry Potter films, and the site now leans heavily into that association — broomstick training sessions run in the outer bailey during the summer. But there is genuine historical substance here beyond the tourism dressing: the Percys were among the most powerful magnates in medieval England, and the castle's history is tangled up with the Wars of the Roses, the northern rebellions, and the long conflict with Scotland. The Fusiliers Museum, housed in the 14th-century Abbot's Tower, covers the history of the Royal Northumberland Fusiliers with real seriousness.