Concrete Tower Inserted into Medieval Castle: A Clash of Old and New

Design a town hall in the manner of Gottfried Böhm's Bensberg — a raw concrete tower and wing built hard against the surviving walls of a medieval castle, matching the old fortification in mass and silhouette but making no attempt to match its material. Compose an angular board-marked concrete tower rising beside a rough stone castle keep, the two touching directly with no expressed joint, narrow vertical slot windows in the concrete, the old ramparts continuing into new walls, a cobbled courtyard, flat grey light, eye-level three-quarter view of the junction, 28mm lens, architectural photography, ultra photorealistic, 8K