Heritage Open Day: See behind the scenes at the Broadbent Theatre, one of Lincolnshire's greatest hidden gems! Be amazed at what lies behind the entrance to the Broadbent Theatre. This quirky little theatre is steeped in history which you can read about in our archives. Whilst you're here, why not follow in famous footsteps and tread the boards! And after all of the excitement, chill out in our green room with some refreshments.