The Yukon is a river of beauty and dangerous extremes - a place where the 'call of the wild' is still strong. Home to grizzlies, moose and salmon, it lies at the heart of a vast northern wilderness.

Bill Nighy narrates the stories of epic train journeys that cross the most beautiful mountain landscapes on the planet, from Canada's Rockies to the snowy peaks of Switzerland and the gorges of Mexico.

Deep in Alaska, the primal way lives on. Fight the freeze, brave the wild, hold on to your sanity. And winter is no wonderland when temperatures plummet far below zero. This series follows the drama and hardships experienced by Alaskan households in different corners of this merciless territory as they battle to survive, thrive, and live life on their own terms.

Ben Fogle travels round the world to visit people who have given up the rat race.

In this special programme on mental health, Michael Mosley runs an experiment to find the best way to beat stress - mindfulness, yoga or gardening. We also discover how sleep affects mental health and why laughing can be as good as exercise for improving mood.

Can they face their fears? Celebrities take on epic adventures and freezing temperatures with Iceman Wim Hof. He'll push their minds to the limit - will he change their lives?