George Clarke's National Trust Unlocked

George visits the majestic 1,000-year-old Dunster Castle in Somerset, once home to a clan who spent six centuries renovating it from fortress to family home. He discovers it's not size that matters at the country's finest surviving 17th-century water gardens, Westbury Court in Gloucestershire, and goes back to his roots in Tyne and Wear at Washington Old Hall, the ancestral home to the first president of the USA. George then trumps it all with a walk around the glorious Croome Park in Worcestershire, the 32-year labour-of-love of 'England's Greatest Gardener', 18th-century landscape architect Lancelot 'Capability' Brown.

George heads for Northumberland, where he takes in one of the most modern Victorian houses in existence - the water-powered, cliff-top mansion Cragside. He also adds his name to the list of dukes, earls and viscounts who've made the astonishing Grade I-listed Cliveden Gardens their playground over the past 300 years, and investigates the unique home of a fellow architect at Snowshill Manor in the Cotswolds, a treasure trove of more than 22,000 curiosities collected from all around the world.

George visits the magnificent and meticulously crafted country retreat of Standen in West Sussex - one of the best examples of the Arts and Crafts design movement to be found anywhere in the world. He discovers a masterpiece of Gothic Revival architecture at Tyntesfield in Somerset, with its acres of flower-filled terraces, and unleashes a medieval catapult at Corfe Castle in Dorset, an iconic ruin who's first stone was laid almost a millennium ago, before risking vertigo with his trusty companion Loki at the highest point on England's south coast - the famous Golden Cap.

In Devon, George visits one of the National Trust's quirkiest buildings, a bear hut on the 6400-acre Killerton estate. The main house was given away because of the socialist ideals of the aristocratic family who lived there. George unearths secrets and scandal at Baddesley Clinton Hall, a fortified Tudor manor house in Warwickshire where in the past the architecture has meant the difference between life and death, then heads home to the north-east for a walk through Gibside Estate, a landscape park with royal connections and crowned with jaw-dropping architecture.

The presenter heads to one of Britain's grandest 17th-century powerhouses - the decadent Ham House - and learns about the remarkable matriarchs who put it on the map, before exploring the Thames-side formal gardens that surround it. Plus, George has a private tour at the modernist Hampstead home of one of his heroes - architect Erno Goldfinger, the man thought to have inspired James Bond's nemesis.