Heritage Open Day: After exploring the Guildhall — visit the museum for children's activities and Design a cell After exploring the Guildhall — once Tavistock’s police station and magistrates court, where justice was served for generations — pop over to the Museum of Policing to delve deeper into crime and punishment through the ages. Discover historic policing displays, hear stories of local law and order, and get hands-on with a fun family craft activity: “Design a Cellâ€.