(CNN)Don McCullin has seen enough of war and suffering to last a lifetime. From Cyprus to the Congo, he has captured some of the most powerful photographs of our time. The shell-shocked U.S. Marine gripping his gun with a long, bewildering stare. A starving twentysomething mother trying to breastfeed her child in Biafra.
Photographer Don McCullin reflects on a life on the front line
So why on earth did he decide to go back to Syria less than a month ago at the age of 80?
"Of course, I was devastated when I heard the news about them [ISIS] destroying the Temple of Bel," he tells Christiane Amanpour in a wide-ranging interview.
"So I rang The Times newspaper when I knew Palmyra had been captured. And I said, 'Wouldn't it be a good idea if I went back, and photographed this extraordinary tragedy?' And they said, 'We would be interested.'"
So off he went to the world's most dangerous place for journalists.
"I didn't consider the danger," he explains, "but it's in my blood. It's what I've done for the last 60 years."
McCullin, who has been described by his former editor Harold Evans as "a conscience with a camera," started his career with his now famous picture of the Guvnors, a north London gang he went to school with in Finsbury Park.
"It was amazing to think that the day I took that picture, my whole life changed," he says. "I didn't seek to become a photographer. It seemed as if it sought me out."
It was during his stint in the Royal Air Force that photography came to McCullin. He started by painting numbers on cans of film and also worked as a photographic assistant in aerial reconnaissance.
After freelancing for The Observer, which sent him on his first war assignment to Cyprus in 1964, and other magazines, McCullin became a staff photographer at The Sunday Times. He eventually made his name with photographs of the construction of the Berlin wall and his extensive coverage of the Vietnam War.
But bearing witness to so many massacres and hardship took its toll on McCullin, who says he has tried to cure his "dark periods."
"I've never really sought any help, because I thought I was always so I'll deal with it myself. And I do that by... I photograph the English landscape where I live in Somerset."
In fact, McCullin doesn't want to be known as a war photographer.
"You know, the war thing, I'm not proud of it," he tells Amanpour. "I find it difficult to feel rewarded at the cost of other people's suffering. So it's uncomfortable."
"I want to leave a legacy of something that is not calling me a war photographer."
"But can you imagine if people like you weren't there? It would be much worse," Amanpour tells him.
"If we hide things and we don't bring them out in the open, we'll never know," McCullin tells her, adding that "if we don't know, it means that people will go on suffering. It's not right."