Hidden Treasures of the National Trust

A painting's hidden story is revealed, a beautiful Chinese bridge is painstakingly rebuilt, and a 450-year-old table must be saved from collapse, ready to go on tour.

A collapsed ceiling means restoring writer Vita Sackville-West's study from scratch, while Rudyard Kipling's family history is revealed in a precious possession.

Paul McCartney's childhood home is lovingly restored; uncovering a unique collection of photos in Liverpool; and an intriguing modern art installation is saved from collapse.

A unique Victorian clock is brought back to life, a portrait damaged by Georgian partying is restored, and an unusual handmade puppet reveals a hidden World War II story.

Winston Churchill's D-Day memento needs reinforcements, antique Chinese wallpaper comes under insect attack, and a Victorian A-lister's stage costume is saved for one last act.

The battle to save unique dodo and dinosaur statues in a Northern Irish garden, the hidden story behind a portrait and a Victorian garden seat's restoration to its former glory.

Every year, millions flock to the homes and gardens of one of Britain's most important cultural institutions: the National Trust. Behind closed doors, dedicated teams of conservators, volunteers, curators and other experts battle to keep our priceless heritage alive.In this episode, an exquisite gallery made of seashells needs shoring up, a priceless Rubens is saved from falling down and an ancient Egyptian obelisk is cracking up.

A look at the teams who care for two luxurious mansions on the edge of London that have long played a pivotal role in society through the lavish parties and country house weekends they hosted: Cliveden House, the former home of Nancy Astor, and Polesden Lacey, the weekend retreat of the heir to the McEwan's brewing empire, Margaret Greville.Meanwhile, an Edwardian clock tower is running out of time, and a Renaissance balustrade needs an intervention.

A missing masterpiece - Penelope and Euriclea, by groundbreaking female artist Angelica Kauffman - returns to its stately home, the grand Palladianvilla Stourhead, after two centuries. Plus the search for the lost castle of Stourton and the scrapbooks revealing one man's mission to save English country houses.

A look at the teams who care for the some of the most important legacies left to the National Trust, from an aristocrat's hoard of priceless treasures to the modest family home filled with everyday objects from 1920s middle-class life.Behind the leaded windows of the Cambridgeshire mansion Anglesey Abbey lies one of the National Trust's most extraordinary collections: 15,000 objects amassed during the lifetime of one man - Urban Huttleston Rogers Broughton, 1st Baron Fairhaven.Meanwhile, in Worksop, a modest semi-detached family home is a perfectly preserved time-capsule of early 20th century life. And the team that care for the Trust's largest fashion collection, based at Killerton House in Devon, are selecting pieces to display in their annual exhibition - no easy task with over 20,000 items to choose from.

A look at the teams caring for two houses which served as launchpads for the soaring ambition of their owners.Saltram House, in south Devon, was once the country seat of the Parker family. But its 18th-century carpet, designed by architect and interior designer Robert Adam and knotted by Axminster founder Thomas Whitty - is in dire need of restoration, leading to a protective re-weave of the original design by Axminster themselves.Meanwhile, the house's 18th-century occupant Theresa Parker is also receiving some essential treatment: renowned portraitist Joshua Reynolds captured the spirit of a young Theresa in a once-striking portrait that's now in need of reviving before it goes on loan for a major exhibition of Reynold's work.Nestled in the Chilterns, Hughenden Manor is a house that helped propel Benjamin Disraeli to the very peak of power. But in the grounds, the once gloriously golden carriage gates that welcomed his guests are in need of restoration. Blacksmith David takes on the daunting task with the help of blood, sweat and a wedge of gold leaf.

At Chirk Castle, a very rare, full-length portrait of a servant from the 18th century reveals its secrets. And in Oxburgh Hall, on the edge of the Norfolk fenlands, two rare hidden treasures - a rat's nest found under floorboards containing scraps of clothes that could be centuries old, and an overlooked portrait tucked away under the stairs - are brought back into the light.

In this episode, the houses that became retreats, and places of inspiration, for three literary legends. At Hill Top, the countryside escape of Beatrix Potter, a collection of over 70 miniature pieces under the roof of Beatrix's own dolls' house is undergoing major conservation before a new exhibition. The tiny woodland cottage of Clouds Hill, Dorset, was a refuge for TE Lawrence, popularly known as Lawrence of Arabia. In the sparsely furnished upstairs room, a portrait of a young soldier on a Cornish beach has sparked debate on whether it portrays Lawrence himself. Lamb House in Rye was the home of celebrated Victorian writer Henry James, who wrote many of his greatest later works in the house's Green Room. Today, James's writing room is looking a little off-colour, and a damp problem means the walls are in urgent need of replastering and repainting.

The compelling and sometimes scandalous family stories behind two very different National Trust houses are revealed.In Knole House, the sprawling Tudor ancestral seat of the Sackville family, a life-size nude statue of 18th-century ballet dancer Giovana Zanerini, commissioned by her lover John Frederick, is being conserved to slow the aging process and restore her legendary looks. Two other heirlooms at Knole - a set of 400-year-old rolled-up animal skin parchments - are so delicate that they haven't been unrolled for many years.At the traditional Lake District farmhouse Townend, a key part of the archive of the Browne family of yeoman farmers - a bound volume of 18th-century letters - is being conserved using traditional book-binding skills, and scientific paint analysis has revealed the house's original Victorian paint scheme.

Kedleston Hall was once home to Lord Curzon, the viceroy of India at the height of the British Raj. The famous Peacock Dress - named for the embroidered peacock feathers that cover it - can be found in Kedleston's collection. Famously worn by Lord Curzon's wife, Mary, it's now in dire need of repair.Meanwhile, at the baroque mansion of Dryham Park in Gloucestershire, conservation work is needed on a rare but damaged painting of the port of Bridgetown, Barbados, which belonged to 17th-century colonial bureaucrat William Blathwayt. Barbados at the time was the centre of sugar production and intrinsically linked with the horrors of slavery, and the painting is thought to show an important but unknown event in the island's history.

A look at the battle to save the homes of two formidable women who refused to bow down to the enemies at their gates but who suffered very different fates after the English Civil War.In west London, on the banks of the river Thames, sits one of the grandest Stuart residences in England – Ham House. Ham was home to Elizabeth Murray, who would become the Duchess of Lauderdale. From a staunchly Royalist family, she was able to find personal favour with Cromwell while secretly supporting the future Charles II. Richly rewarded for her loyalty, many of her most prized possessions are in desperate need of repair and conservation.Watching over the Purbeck Hills in Dorset are the remains of Corfe Castle, home to another set of Royalists - the Bankes family - who suffered a very different fate. Lord Bankes's wife, Mary, is said to have personally defended the castle against Parliamentarian forces until a traitor in her ranks let the besiegers in. Now, the National Trust are undertaking their biggest ever conservation project at the castle.

A look at the homes of three men who changed British life through art, culture and architecture.In Hampstead lies the former home of architect Erno Goldfinger, a pioneer of postwar high-density housing and the creator of many iconic buildings, such as the Trellick and Balfron towers in London. His collection of avant-garde art aimed to complement his designs for modern living, but a piece by Argentinian artist Hugo Demarco is in need of conservation work.At Upton House, the 1930s country retreat of art lover and National Gallery chair Walter Samuel, Lord Bearsted, major work is needed on one of the highlights of his collection, Tintoretto's The Wise and Foolish Virgins. And a mysterious letter has recently been donated to the collection at Carlyle's House in London, revealing how sought-after the company of literary giant Thomas Carlyle and his wife Jane really was.

A look at the homes of two families who battled to defend their beliefs and the divinely inspired masterpieces they contain.In the shadow of Bodmin Moor lies the grand Jacobean mansion Lanhydrock, the family seat of the Robartes family. Its grand long gallery, a 17th-century survival of a 19th-century fire, is undergoing a huge conservation project, with every single square centimetre of the ceiling requiring cleaning, stabilising and repainting.In Warwickshire, an even larger conservation project is in progress. At Tudor manor Coughton Court, the very fabric of the building needs essential work, without which the historic collection inside the house is at risk. A specialist team are on site to preserve, repair and improve the roofs and facades of the building.Meanwhile, a rare Catholic treasure from the house's collection - the Tabula Eliensis, a unique painting of the coats of arms of Catholic gentlemen interned by Elizabeth I - needs to be sent away for essential conservation. The roof project has presented a unique opportunity: using a crane to hoist the tabula out and up into the air through a tiny slot cut in the ceiling before the new roof is in place.