George Clarke's National Trust Unlocked

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.

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.

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.

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.