Grylls talks about why this series is the toughest adventure race in the world, and why it's the viewing we all need during lockdown.

Bear Grylls is sitting on a green hill with a view of the ocean sprawling behind him in the distance.

"I'm in north Wales, we live on a little island up here," he explains.

"The mainland is a couple of miles that way (he points his right arm out alongside his body), storm clouds are coming in," he adds, looking up at the grey sky.

"(It's) off grid, off mains, electricity and water, (a) beautiful place, (a) happy place for me."

It also could not be a more perfect setting for Grylls, 46, to enthuse about his latest project, the new Amazon Prime Video series World's Toughest Race: Eco-Challenge Fiji.

Grylls hosts the series, which features 66 teams from 30 countries racing non-stop for 11 days, 24 hours a day, across hundreds of miles of rugged Fijian terrain complete with mountains, jungles and oceans.

The 10-episode series was filmed last autumn in Fiji and features 330 competitors who form teams of five, including four racers and an assistant crew member.

They will cover 671 kilometres (417 miles) of terrain in a test of physical and mental endurance, in a bid to cross the finish line.

"Fiji was an incredible setting for the World's Toughest Race, just because it's harsh, you know, people think of it as a beautiful, Pacific island, but don't be deceived," he cautions.

"It's huge and it has everything. So, we had races going for 671 kilometres, huge distances, across high mountains that are freezing cold, down to 100% humidity rainforests, miles of swamps, grasslands, rivers.

"You've got the ocean, so these adventure racers really went through it all, and then you have the human factor of what it's actually like of trying to keep a small team of four people alive and moving and going forward when you haven't slept for 10 days, and you're dehydrated and exhausted and you're hungry, and you're still having to make good decisions about your navigation.

"That's why it is the world's toughest race. And what people went through - mind blowing."

The rebooted series is produced by Mark Burnett, who is responsible for the US versions of The Apprentice and Shark Tank.

Former SAS serviceman and Chief Scout Grylls is no stranger to braving and conquering the elements himself.

His Running Wild With series has seen him take on the most stomach-churning environments, with prominent guests including former US president Barack Obama.

The son of politician and former Royal Marine Commando Mickey Grylls, he was recognised in the Queen's Birthday Honours last year with an OBE for services to young people, the media and charity.

So, as the setting for this interview (done via video) shows, the outdoors is home.

But how did he feel presenting and not participating?

"It's impossible not to feel that emotion, we're so involved with these races, the preparation beforehand, their training and just what they've given to be on that start line.

"And then once the race starts I'm right amongst it all the time with them, but also with their support crews and what they all go through is truly inspirational," he says.

"When you see the tears and what people are giving to just endure and just hang on and to keep moving.

"When you see blood being poured out of boots and blisters, and yet relentless positivity and determination to hold the weakest member of the team and to still go on, it was really mind-blowing at times.

"It was a reminder for me, in an era where the world desperately needs inspiration, it was a reminder of the power of friendships and what you can do together, when you help each other and when you're honest and vulnerable with each other.

"But also a reminder of the power of the human spirit, that resilience, that fire inside of all of us, that it can conquer everything when everything is against you.

"I had tears in my eyes regularly on the World's Toughest Race."

The diversity of the teams was another heartening element of the series. Twins Tashi and Nungshi Malik, from India's Team Khukuri Warriors, wanted to inspire women.

Nungshi explains: "Coming from a country such as ours, India, we're still not an outdoors nation. It's a field that is particularly viewed as reserved for males.

"Women doing anything in the outdoors is never seen as sexy as men doing it.

"For us, climbing all these massive mountains, skiing the Poles and adventure racing, really affirms our belief that if we dream big and we commit to it, we can achieve the impossible.

"That's what our message was for the girls in India and across the globe. Nature doesn't discriminate based on gender."

For Team Endure, with adventure race veteran Mark Macy and son Travis among its members, the series was a poignant journey.

Mark, 66, has Alzheimer's disease, but participates in the race alongside the team.

"It was amazing to see, when you see humans overcome incredible adversity, it's impossible not to be moved and inspired.

"That's what I loved about the World's Toughest Race: the regular people, the regular rookies, who've already battled so much in their life, digging deep and leaning on the power of togetherness and taking on what looks like the impossible and coming through it, almost against unbelievable odds.

"It's really moving and really inspiring," says Grylls.

And that message of positive inspiration is the viewing the world needs now, he muses.

"I think the world has never needed positive inspiration more. We've gone through an incredible time of adversity all over the world. Every country, every community, and what I love about the World's Toughest Race is there's such a visual display of the qualities that matter to get people through tough times.

"The power of friendship and the power of resilience, and the ability that you've got to adapt and recover from failure and keep moving forward and to get back on your feet, and to never give up."

World's Toughest Race: Eco-Challenge Fiji launches on Amazon Prime Video in the UK on August 14.