Leonardo DiCaprio visited Pope Francis Thursday at the Apostolic Palace in the Vatican in order to discuss their concern over the environment.

The 41-year-old A-lister bowed and kissed the pope's ring as a form of respect as he greeted him in Italian. "Your Holiness, thank you for granting me this private audience with you," is what DiCaprio said to the pope, according to ABC News.

DiCaprio then proceeded to show the pope a book that contains artworks of Hieronymus Bosch, and specifically the "Garden of Earthly Delights" which he said his father hung a print of above his bed when he was a kid.

"As a child I didn't quite understand what it all meant, but through my child's eyes it represented a planet, the utopia we had been given, the overpopulation, excesses, and the third panel we see a blackened sky that represents so much to me of what's going in the environment," DiCaprio said.

The "Revenant" star showed the painting to the Pope because he though that it is a visual example of Pope Francis' concern towards the current environment which is included in the "Laudato Si." The 2015 encyclical of Pope Francis calls for the end of fossil fuel use and for people to start exploring more environment-friendly sources of energy. DiCaprio, a vocal environmental activist, has worked for years to raise awareness and try to revert the sources climate change, The Los Angeles Times reported.

Both figures addressed the issue on climate change at international conferences recently - Pope Francis during the United Nations General Assembly in September and DiCaprio during the World Economic Forum this January.

The "Garden of Earthly Delights" is a triptych painted in the 15th century on oak panels, which mainly depicts mankind consumed by earthly desires. The first panel shows what may have been the first encounter between God, Adam and Eve. Next is the middle panel, then the last one, which shows mankind in hell's darkness, according to Mental Floss.

The pope was given a check to be used for his charitable endeavors, while DiCaprio received a copy of the "Laudato Si" covered in leather and "The Joy of the Gospel," according to the Associated Press.