Robson Green turns 60 this year and wakes up every morning relieved that he didn’t die in his sleep. But that didn’t stop the Grantchester actor from heading out into one of the most dangerous and oldest wilderness areas in the world.

In his latest series – “Into The Amazon With Robson Green” – the actor and adventurer climbs 45-metre-high trees, takes on fearsome tarantulas and comes face to face with deadly black caimans.

“There are things that can just eat you,” Robson says of the Amazon. “They grab you, kill you and you never see you again. There are caimans, spiders and anacondas, and if they don’t like you, they’ll let you know.”

Robson’s worst wilderness encounter, however, was when he accidentally stepped on a black wasp nest. “I stepped on what can only be described as a hornet’s nest,” Robson says. “Let’s put it this way: These really big black wasps were very excited and decided to let me know how excited they were. They crawled into my clothes and my hair and it really hurt.”

As soon as he entered the nest, Robson’s handler shouted “Run!” and the whole crew scattered. “They would have beaten Usain Bolt in the 100-meter dash!” laughs Robson. “Chris, our sound engineer, was gone like a gazelle, you couldn’t see him for all the dust! I got seven stitches, all in the same place, on my head! They sting more than once and it hurts.”

Encountering a much larger predator should have been terrifying for Robson, but encountering a black caiman left him simply overwhelmed with awe. “I remember being next to a black caiman. We were on this beautiful Amazon boat and there was a black caiman that was about 14 feet long. I just thought if it gets anywhere near me it’s over, it really is ‘goodnight Vienna’.”

“I was able to see it in a completely different light and just say, ‘You are beautiful. You are an apex predator. Nothing will contest you!'”

Robson will be in his seventh decade of life in December, but he doesn’t want to celebrate his 60th birthday properly. “I don’t celebrate my birthdays,” says the actor. “I’ll probably go fishing. I don’t want to remember my age because it’s just a number. You’re only as old as you feel – I’m trying desperately to stay young.”

“Into The Amazon With Robson Green” airs on Tuesday 21 May at 9pm on C5.