Japan

Five young British men take on the challenge of a lifetime - to spend four months travelling the world, taking on some of the most deadly creatures and hostile places on the planet.

They have reached Japan for the last of their challenges. They have just six days to become Buddhist Yamabushi monks and take part in one of the toughest pilgrimages on the planet to the summit of a sacred mountain, under the watchful eye of Miyagi-San, their Master.

The Yamabushi are a centuries-old sect that seeks enlightenment by experiencing nature at its most raw and the Brits have arrived just in time for the Okugake - an extreme pilgrimage to the top of a treacherous mountain ridge that is at the heart of the Yamabushi's beliefs.

It involves four days of climbing, interspersed with physical and spiritual trials including the Nishino Nozoki - which involves being hung over a precipice while answering questions about your beliefs. Over the centuries many monks have been injured and even killed on the pilgrimage.

Before the lads can start the quest they must learn how to live the ascetic life of the monks through meditation and prayer, and prove their mettle by chanting ancient mantras under an icy mountain waterfall.

For Nick, it is his chance to complete every single challenge of the journey, but Ben is still waiting for that one handshake of success. And for everyone, the long, silent journey gives a chance to reflect on how their epic four-month challenge to take on the natural world has changed them as people.