For six months, National Geographic photographer Dave Yoder had extraordinary access to Pope Francis at the Vatican, an experience that he expects he will one day look back on as “surreal.” It took weeks to secure permission to shoot in some Vatican locations, but Yoder persevered. He befriended the pope’s personal photographer, which eventually allowed him to closely shadow the pontiff.

“Once they got to know me, and they trusted me, I was then able to do things that even now seem kind of unimaginable,” he says.

For Yoder, the assignment was stressful and hard—not a spiritual experience. But he says that being in the presence of Francis was “inspirational,” particularly when the pope met with pilgrims in St. Peter’s Square. “I personally can’t think of a world leader who is so frequently greeted and embraced and treated like a long-lost uncle,” he says.