Having a conversation with Benedict Allen is what I imagine chatting to Indiana Jones is like. After all, not many people, when telling you what they did in the year after university, will suddenly, cheerfully diverge into the following anecdote:

‘Lost in the jungle, I was attacked by goldminers and suddenly found myself alone without any supplies at all. In order to escape from them I jumped into a canoe, but the canoe capsized, I walked and walked out of the forest with my dog, but I had malaria and I was starving to death, effectively, and I knew I had to kill and eat the dog if I was ever going to see my mum and dad again.’

As gap years go it beats interrailing around France. This sort of thing, however, is just life for the rugged 49-year-old, who, quite apart from the five books and six successful BBC documentary series’ (his latest venture is Five’s reality show Unbreakable), is that very rare thing in the 21st century West: a bona fide explorer. It conjures up images of daring Victorians, of khaki-clad movie stars, but it’s not the sort of vocation you can imagine being endorsed by your average careers advisor.

‘When I was a little boy I had this dream of being an explorer,’ he says. ‘I clung to it, growing up – it was all I ever really wanted to do. People would say to me, “You can’t be an explorer. The world’s been explored. You haven’t got any money, anyway.” But I clung to this dream. It might have been a very romantic idea, fantastical, even, but I clung to it.’

In 1982, full of the confidence of his early 20s, Allen worked for a year in a warehouse to earn himself enough money for a flight to the Amazon, armed only with a BBC cassette course in beginners’ Spanish.

‘I realised that the people who have always lived in these places that we consider extreme see their surroundings as home, not a threat. I just turned up on the edge of the jungle and asked people to look after me, learned from their skills, and then set off on a journey to test myself. It was a naïve premise, but it worked, and I’ve followed it ever since.’

This experience became the basis of his first book, Mad White Giant, and set him off on a career that eventually led him into television, pioneering the confessional, self-filmed travel documentary. However, as he’s keen to point out in his upcoming series of Royal Scottish Geographical Society lectures, he doesn’t just travel for the thrills of adventure.

‘The world isn’t just a playground. People like me, who go out there, have a duty to convey information. I want to talk to people, convince them that there’s a world out there that we don’t fully understand, and that exploration takes many different forms.’

Benedict Allen will be appearing at Renfield St Stephen’s Church, Glasgow (afternoon) and the McEwan Hall, Edinburgh (evening) on Thu 8 Oct.