Alnwick Castle is a castle and country house in Alnwick in the English county of Northumberland. It is the seat of the 12th Duke of Northumberland, built following the Norman conquest and renovated and remodelled a number of times. It is a Grade I listed building now the home of Ralph Percy, 12th Duke of Northumberland and his family. In 2016, the castle received over 600,000 visitors per year when combined with adjacent attraction the Alnwick Garden.

The River Aln runs through the county of Northumberland in England. It rises in Alnham in the Cheviot Hills and discharges into the North Sea at Alnmouth on the east coast of England.