Heritage Open Day: Grimsby Town Hall Open Days Friday 18th & Saturday 19th September, visit the Time Trap Museum and discover Grimsby's past, see the Great Grimsby Family History display and find out about tracing your ancestors, as well as Archives and other displays. Visit the Great Grimsby Town Hall to see the majestic Assembly Room and Banqueting Suite also the Bremerhaven Room (Former Court) and the Crosland Suite, named after former Foreign Secretary and Grimsby MP Anthony Crosland. Wander around the Council Chamber and view the civic regalia and silverware; you can also see the historic stained glass windows in the Council Chamber. During your visit, enter the Time Trap, this surprising attraction, in the former prison cells of Grimsby Town Hall.