Cragside, Seaton Delaval Hall, Cherryburn

S1, E4: Cragside was the first house in the world to be lit by hydroelectricity. It is filled with engineering marvels, but now the team must carefully restore and replace a priceless clock. Seaton Delaval Hall was home to a family whose hard-partying lifestyle led to them being dubbed the ‘Gay Delavals’. But can conservation experts repair a painting that may have been damaged by a champagne cork?