With an average audience of nearly two million people coming to every episode of series one, Hidden Treasures of the National Trust explores one of Britain’s great cultural institutions. Reflecting the national scale and importance of the Trust’s many properties and the passionate staff and volunteers who help care for them, the series reveals new and compelling stories about the work going on behind the scenes to conserve these incredible properties and objects for us all.

Each episode explores a different central theme, linking the houses, their histories, and collections as they undergo conservation. From graceful Georgian homes that were platforms for political power, to houses that become display cases for the curious collections of their owners and properties designed as show-homes for the English country house idyll.

Ranging across England and Wales, Hidden Treasures of the National Trust documents recent conservation work to tell a host of fascinating stories, including that of Jane and Mary Parminter, unmarried cousins, who in the late 18th century created a unique 16-sided house in Devon known as A La Ronde, in which to display treasures they had brought back from their Grand Tour. Their beautiful Shell Gallery is now needing urgent care. Audiences will encounter the obelisk used to help decipher ancient Egyptian hieroglyphics, but which needs expert repairs at Kingston Lacy in Dorset to preserve it for the future, and follows the teams bringing back the bling to the grand gates of the country home of Benjamin Disraeli, the Victorian prime minister who used Hughenden Manor in Buckinghamshire in his ascent to power.

Alistair Pegg, BBC Arts commissioning editor, says: “I’m delighted to be delving behind the scenes once more at the National Trust, uncovering hidden histories of houses and their owners, secrets of the painstaking conservation carried out on beautiful objects and buildings, and the wonderful staff and volunteers who work, often unsung, across the country.”

Tarnya Cooper, Curatorial and Conservation Director at the National Trust, says: “History comes to life before you at National Trust properties. Across hundreds of places we have well over a million objects, which tell fascinating stories of the generations of people who commissioned, made and loved them.

“Looking after such diverse objects and places takes dedicated teams of people as well as expert conservators, and we hope BBC viewers will enjoy learning more about them and their work on wonderful collections ranging from must-see paintings and furniture to books and textiles to amazing architectural features.”

Hidden Treasures of the National Trust is a Blast! By The Sea production for BBC Two and BBC iPlayer. The executive producers are Sacha Baveystock and Sarah Spencer. The commissioning editor for BBC Arts is Alistair Pegg.