Leonardo DiCaprio has said that 'The Revenant' is one of the most difficult films he's ever accomplished in his life. The film recounts the story of Hugh Glass, a 19th century trapper who, after being mauled by a bear, travels more than 1,500 miles to get revenge on the men who left him for dead.

It took Leo some serious training to play the character.

During the nine-month shoot, Leo and the team traveled to four different locations to get just the right shots:

– Tierra Del Fuego, Argentina
– Montana, USA
– Alberta, Canada
– British Columbia, Canada

The frigid temperatures and unforgiving terrain of these locations made it extremely hard to shoot the movie.

Leo recalled that storms would come out of nowhere, plunging temperatures below negative 40 degrees Fahrenheit.

Because of the lack of natural light, they had to rehearse scenes all day until they had about one and a half hours of perfect light to nail a shot.

Leo explains that this is the hardest professional work that he has ever done, and there are at least 30 to 40 moments that he can recall that stretched his limits to the max.

When you see scenes of him battling the rapids of a rushing river, that’s actually him in extremely cold water.

His biggest moment of immersion is when he eats a Bison liver. Many people think this is a prop, yet it was actually a raw liver, despite the fact that Leo is a vegetarian.

Leo endured five hours of makeup per day including getting hot wax dripped on his beard to make it appear as if ice had formed in his beard.