King Charles III is offering royal watchers a rare look at one of his private residences. The trailer for Charles' upcoming documentary, Finding Harmony: A King's Vision, dropped on Thursday, January 1, and showed the 77-year-old monarch looking relaxed at home. Fans quickly noticed that the never-before-seen residence was none other than his Gloucestershire countryside home, Highgrove House. One clip showed Charles smiling while watching his old speeches about the environment from a plush chair in what appeared to be a projection room.