Martin Sheen originally suggested Michael Douglas or Mel Gibson for the lead role, but Emilio Estevez had written the main character's role specifically for his father.
When one takes the 500 mile Camino de Santiago, they carry a scalloped shell with them as an identity. Emilio Estevez was given such a shell by a man who made that journey six times. When he made the journey while filming the film, he kept the shell with him.
Filmed with a small crew of fifty people and a couple of cameras for filming. No trailers were used, and, as Estevez jokingly remarked, neither was a director's chair.
According to the producers, who were asked that question during a Q&A held in New York on Oct. 6, 2011, they instructed the prop department to adorn the backpack so that it reflected his son Daniel's extensive travels.