Dominating the small riverside town below, this vast, gray hilltop castle, surrounded by castellated walls, was first built by the Normans but only the keep is from that period. During the 16th century it was acquired by the powerful Dukes of Norfolk, the country's senior Roman Catholic family, who still live there. They rebuilt it after the original was virtually destroyed by Parliamentarians in 1643, and restored it again in the 19th century.