Festival-goers will be able to enjoy a new theatre in the grounds of an historic medieval castle from May. The roof of the outdoor theatre on Two Sisters’ Lawn at Hever Castle, near Edenbridge, was destroyed in July last year when a falling tree struck it. The venue in the grounds of Anne Boleyn’s old home hosted the Festival Theatre, which has been running for the past 40 years. But a new theatre will be constructed next month in time for the event to start in May. And whereas the old damaged performance centre had a roof that only extended a little over the stage – with audience members expo…