They may be among the most successful films of all time, raking in billions of pounds around the world, but making Peter Jackson's Lord Of The Rings trilogy was anything but glamorous. The cast had to wade through mud, blood and dead bodies during the gruelling 18-month shooting schedule in New Zealand - and it nearly ended with one of the cast losing his life.

Viggo Mortensen, who plays the handsome and fearless warrior Aragorn, is well known for throwing himself headfirst into any role he takes on. And, with the third part Return Of The King released on Wednesday, he recalls that filming the epics was no exception.

He managed to catch athlete's foot from walking around barefoot, got lost at night while trekking on his own through a rainforest, had a tooth knocked out in a sword fight - which he stuck back in with chewing gum - and broke two toes when he kicked a metal helmet in frustration.

But another incident convinced Viggo, 45, that his time was well and truly up.

"I was in a river, down on the South Island, when I got caught in a current," says the New York-born actor. "I had all my gear on and was pulled straight to the bottom of the river. The water was cold so that I could feel my lungs constricting.

"It was one of those beautiful New Zealand rivers and I remember, just as I started to black out, that it was a really sunny day and that the river looked lovely. I did think, 'This is really it', because nobody knew I was there.

"Then, somehow, I managed to kick against a rock and get myself out of there. It was just a brief, very dangerous moment but, of all the things that happened during this movie, that was the one where I genuinely thought my time had come.

"I think I'm more accepting of my own mortality now. I don't resent the fact that I'll run out of time to learn new things or do things in life. In the past, I felt that it was unfair at times, because I'd only just showed up on this planet. I'm interested in this world and I want to see a lot more of what happens here!

"I'm not sure why I feel that way now. It's probably a combination of things and maybe just a function of being a few years older and seeing other people suffer, get ill, get old and die. I also think it's to do with an appreciation of this story, because it's reinforced my feelings about sacrifice and compassion. It makes you value just what you've got."

Mortensen, who was born to a Danish father and an American mother, got his initial break playing an Amish farmer in the 1985 Harrison Ford drama Witness. A keen jazz guitarist - he's released three albums - poet, photographer and accomplished painter, Viggo is very much his own man and his brush with death didn't stop him taking further chances while shooting The Lord Of The Rings.

"One time, I was in the rainforest near the west coast of the South Island," he recalls. "It was on a shooting break, one of those incredibly rare weekends where I actually had a Saturday off. So I just went down there for a day and a night to a place that I'd been to before.

"I wanted to get to the coast, so I headed into the woods, but it was a bit of a hike and it suddenly got dark. I hadn't brought a flashlight with me, which was a bit stupid, because I thought I knew the trail really well. But then I got lost.

"There was no moon and it was overcast, so it was just completely pitch black, especially as the vegetation was really dense and thorny. But I did have a camera with me, which had a flash, and a couple of rolls of film.

"So I used the flash to try and find my way out. For a second you could see everything around, so I was using the flash to try and find the trail. I kept thinking, 'It must be around here somewhere', but I never did find it. And then I ran out of film."

Faced with the prospect of just wandering around in circles, Mortensen decided that his best plan was to stop and find somewhere to settle down for the night.

"At some point I was just getting really tired and ended up in a marshy area," he says. "I was falling down all the time, getting cut by thorns and I thought, 'This is stupid'. So, I found a piece of relatively high ground and lay down for a little while, until the moon came up.

"Luckily, when the moon arrived I managed to get my bearings and eventually I was able to figure out how to get back to where I started from. It was a huge relief, but when I showed up back on the set, I really alarmed everyone because it looked like I'd been through a grinder."

After this sobering ordeal, Mortensen finally learnt his lesson and stopped disappearing on his own. But he will always have a reminder of those hours lost in the rainforest, courtesy of the roll of film he shot while trying to find his way out.

"When I developed the film, which was black and white, there were some really interesting images," says Viggo. "The flash had lit up the ground, the foliage and these ferns which are typical of New Zealand. Some of them are almost like negatives because there was this fog and the flash was bouncing off them creating a really strange effect.

"It's quite unusual because there are these delicate ferns with their little tendrils and all the whiteness around them which makes them look like Japanese prints. I printed off four of them, which I've called Lost 1, 2, 3 and 4. You can see them on the internet."