In 1999 he went to Thailand to be in the film the beach. This film is about a number of young people who go to live on a beautiful beach, a long way from towns and people. The people making the film found the island of Ko Phi Phi Leh, which was very beautiful. They brought in a lot of trees which do not usually grow there and put them around the beach. When they finished the film they took away the trees and tried to make the beach the way it was before. But some people were very angry about the changes to Ko Phi Phi Leh. Perhaps it will be a long time before the beach is beautiful again.
Film stars come and go, but Dicaprio is still interested in the environment. In 2007 he made a film called The 11th Hour, about the problems of the environment today. "The danger is now" , the film tells us.