Comedian Sue Perkins and adventurer Charley Boorman travel across Alaska to the notorious Dalton Highway - a dirt track built in the 1970s as a supply road to support the Trans-Alaska oil pipeline. Highway maintenance is a full time job here with avalanche units operating throughout the year. As Arctic conditions close in on them, the pair have to rely on the help of hardcore truckers for whom the highway is home. The rules of the road are: keep the CB radio switched on, don't exceed 50mph, and when an 18-wheel truck comes thundering down the rollercoaster of a road towards you, get out of the way!

Comedians Rhod Gilbert and Greg Davies attempt to drive through the mountainous, landlocked nation of Nepal.

Ben Fogle and Hugh Dennis travel from the Peruvian Andes to the depths of the Amazon, in search of the lost city of Constitucion.

Ed Byrne and Andy Parsons brave temperatures as low as 50 below to drive across Siberia's infamous Road of Bones.

Sue Perkins and Liza Tarbuck drive the legendary Ho Chi Minh Trail, a network of dangerous roads hacked through mountains and jungles of Laos and Vietnam.

Hugh Dennis and David Baddiel drive Ethiopia's bone shaking roads to reach Askum, home of the Ark of the Covenant.

Hugh Bonneville and Jessica Hynes take a terrifying road trip through the former Russian state of Georgia.

Funny men Phill Jupitus and Marcus Brigstocke head to Bolivia for a high-altitude road trip that promises adrenalin, hilarity and drop-dead beautiful scenery. Already good friends, the terrified duo first have to survive Bolivia's infamous Road of Death only to find themselves deep in notorious bandit country. Disorientation takes them by surprise as they have to navigate the stunning Salar de Uyuni, a salt lake so vast that Buzz Aldrin could see it from space. Their goal is to reach the ancient mountain city of Potosi whose silver once financed the great Spanish empire but at almost 5000 meters above sea level this proves to be a heart stopping finale.

Actor Will Mellor cajoles one of his best mates - comedian Keith Lemon - to join him on a high-octane road trip in Albania.

Another thrill-seeking adventure, this time with long-term mates Joe Wilkinson and Zoe Lyons - who've travelled to gigs together for years - taking on the wilds of eastern Turkey.

Certified 'indoorsman' Phil Wang convinces best friend Pierre Novellie - also not much better at outdoor stuff - to join him in Africa's Kingdom in the Sky.

Another thrilling escapade in the wild - this time sees actor Stephen Mangan and comedian Lara Ricote, who have never met before, aim to reach the northernmost point of Australia.

Ed Gamble and Lou Sanders have been friends for years, so much so that she's bought a 'his 'n' hers' set of driving gloves to tackle a dangerous 1000 kilometres of Iceland.

Jamie-Lee O'Donnell and Saoirse-Monica Jackson, who are best friends and stars of the hit sitcom Derry Girls, head way out of their comfort zone as they tackle rugged Romania.

Darren Harriott is a former bouncer and self-confessed city boy, while Ria Lina is full of adventurous spirit with a PhD and autism. How will they fare travelling in South Africa?

Comedians Maisie Adam and Suzi Ruffell wouldn't call themselves road aficionados - it took 10 goes to pass their driving tests between them - but they're tackling Morocco anyway.

Rhod Gilbert and friend and fellow comedian Angela Barnes cross Italy's most treacherous Alpine roads in Rhod's first adventure since being treated for cancer.

Joe Swash and Seann Walsh are no strangers to jungles after appearing on I'm A Celebrity..., but neither of them has sought an ancient Mayan temple in Guatemala before.

Former Soccer Saturday buddies Jeff Stelling and Chris Kamara reunite for an epic journey across Sri Lanka where they reaffirm their friendship along the way.

Mike Wozniak and Ola Labib head to one of the wildest places on Earth - the Namib desert - to meet for the first time and have each other for company on their journey.

David Harewood and best friend Fraser James swap the sets of Hollywood for a new challenge in Slovenia where they face some of the most dangerous roads in Europe.

Jess Fostekew and her good friend and fellow comedian Desiree Burch take on an utterly insane trip across Colorado's Rocky Mountains in a Wild West adventure.

Jamali Maddix and Larry Dean experience the Land of the Thunder Dragon, a place of mystery and wonder in the rarely-visited and remote kingdom of Bhutan.

Olga Koch and Thanyia Moore - who are friends from the comedy circuit - head to Bulgaria for a high-octane adventure that takes them across two epic mountain ranges.

Old friends and fellow comedians Johnny Vegas and Lucy Beaumont take on perilous mountain drops and sheer cliff edges in a hair-raising trip on Montenegro's roads.