The castle that gave Newcastle its name. The 12th-century keep and the 13th-century Black Gate are all that survive of a much larger Norman fortress, the rest of which was demolished in the 19th century to make way for the railway viaduct that now passes directly between the two buildings.
A combined ticket gets you into both structures. The keep is the more rewarding climb — narrow spiral stairs to the battlements with views over the Tyne — while the Black Gate has the historical exhibition. Worth an hour.