Explorer Benedict Allen presents this brand-new adventure series. Eight volunteers undergo an onslaught of physical and mental pressure in a bid to be declared ‘unbreakable'. Filmed across four continents, Unbreakable takes eight super-fit members of the public on a punishing global trail to undergo a series of brutal challenges. From the Norwegian arctic to the Sahara Desert, the volunteers will learn to survive in the world's harshest environments and endure some of the toughest military training around. They will be bossed and cajoled by physical trainers and survival experts as they bid to outdo - and outlast - each other.