Chinese philosopher Lao-tzu said, “A journey of a thousand miles begins with a single step.” So does a journey four times as long and a hell of a lot more dangerous. For intrepid explorer Levison Wood, the first of 7 million steps began high in the jungles of Rwanda, the source of the River Nile, and ended nine months and 4,200 miles later at the Mediterranean Sea. In November 2013, Wood set out to do something no man had done before: walk the length of the world’s longest river. His trek through six East African countries — dodging bullets, minefields and deadly animals, weathering heat, thirst and blistered feet along the way — is the subject of the Animal Planet three-hour special “Walking the Nile,” which premieres on March 18.

A photographer and journalist, Wood chronicled his experiences in images and words, both for the documentary and a companion book of the same name. Formerly a captain with the British Parachute Regiment who fought Taliban insurgents in Afghanistan, Wood found himself back in hostile territory as his route took him through the war zone of South Sudan and areas where robbers, poachers and armed rebels threatened his safety. There was tragedy when a companion died of heat stroke and he was powerless to help. But there were also unforgettable moments like flying in a hot air balloon over the Valley of the Kings or spending time with the gracious Mundari tribe and learning their customs. Wood shared his thoughts on these moments and more in this wide-ranging Q&A.

You say it was your lifetime dream to walk the Nile. Why?

Levison Wood: I’ve always been fascinated by East Africa. I’m a student of history and I have traveled there a lot as a writer and a photographer. This was the culmination of 15 years’ work for me. One of the other reasons I wanted to do this was to raise awareness about issues in Africa, the main one being conservation. I wanted to show people that Africa is changing very quickly, and unless something is done about it a lot of the wildlife will be extinct very soon. Elephants, for instance, will be completely extinct in Africa from poaching if something is not done about the ivory trade. That’s not in the documentary — unfortunately, there are only so many stories you can tell.  But for me, it was very important, and it’s covered in my book.

It took two and a half years of preparation, not necessarily physical. It’s more doing your homework: learning about the political and cultural situation. I went to Africa to learn about wildlife behavior, like figuring out what to do when a lion gets close. That’s more important than the physical training

I could only take with me what I could carry because I was on foot. I only took the essentials. Most of the stuff you could really get along the way — food and things like that. It was only the technical gear, like satellite phones, that I had to take. I thought it would be a good idea to take a laptop but it was too much weight, so I ditched that and used my iPhone.

You went to danger zones—did you think about bringing a weapon?

I didn’t think about bringing a weapon because if you’re armed you’re asking for trouble. There were times I had to employ local rangers, militia or police to help me out and keep me safe.

At 21, when I finished University — I studied history at Nottingham — I hitchhiked from England to India and all the way through Iran, Iraq, Turkey, Afghanistan and Pakistan. I ended up carrying with it as my profession. I don’t think I’ve ever had a job. I made my own career as a freelance photographer and writer. When I left the military full time, I set up a company that specializes in taking journalists to places, “fixing” things for them.

I couldn’t have done this without the military experience. I spent five years with the regulars, and a stint before and after in the reserves. The military gives you a certain mindset. It trains you to push yourself to the limit and beyond. You can achieve anything really. You learn about survival, learn about understanding risk — what’s dangerous and what isn’t, and not to be scared just because somebody’s got a gun. It gave me a better understanding of what the dangers were.

Even so, were you nervous as you set out?