Alnwick Castle is a historic and grand castle located in Alnwick, Northumberland, England. It has been the home of the Percy family, the Dukes of Northumberland, for over 700 years. The castle was originally built following the Norman Conquest around 1096 and has been renovated and remodeled multiple times since then. It is a Grade I listed building and is the second largest inhabited castle in the UK after Windsor Castle. The castle has a rich history of battles and sieges and has served various roles including military outpost, teaching college, and film location for productions like Harry Potter and Downton Abbey. Adjacent to the castle is the Alnwick Garden, a major formal garden attraction featuring a poison garden and a large treehouse complex. The castle's construction features a shell keep with Romanesque archways and towers added in the 14th century, along with later Victorian restorations by Anthony Salvin. It is located on a strategic site guarding a river crossing, with parks landscaped by Capability Brown. Today, it is a popular tourist destination offering exhibitions, a museum, family activities, and cafes. Alnwick Castle combines historical significance, architectural grandeur, and family legacy in a well-preserved medieval setting.