To learn his ways around animals, the actor portraying the shepherd (the three times Goya-award-winning actor Luis Tosar), had training from a local shepherd who ended up acting as a double for scenes with its herd and his dog (that also ended being in the movie), as well as technical advisor for the whole movie. The house where the crippled lives in the movie is, in fact, where that local shepherd, Ángel Martínez, lives himself.
The small train stop and the battered railroad tracks that appear in an important scene of the film were built specially for the shooting, they are located in a regular street where cars actually pass through. The church just by the station doesn't have the small fence that surrounds it either.
The tourism website of the region in Spain where it is shot (Granada, in eastern Andalusia) offers a 76 km long bike trail that visits most locations of the movie.
Epilogue/Dedication: "A todos los enseñan a perdonar" (translated as--To all those who teach how to forgive).