Alnwick Castle is one of England's largest inhabited castles, home to the Duke of Northumberland and instantly recognisable from the Harry Potter films where it doubled as Hogwarts. The castle's magnificent State Rooms display Renaissance paintings and Meissen porcelain, while the adjacent Alnwick Garden is a contemporary masterpiece featuring the Grand Cascade and the intriguing Poison Garden. The market town itself retains medieval character with cobbled streets, independent shops, and the world's second-largest second-hand bookshop in Barter Books.