Guns for San Sebastian is a 1968 action-adventure film based on the 1962 novel A Wall for San Sebastian, written by Rev. Fr. William Barnaby "Barby" Faherty, S.J. The film is directed by Frenchman Henri Verneuil, and stars Anthony Quinn, Anjanette Comer and Charles Bronson. The score is by Ennio Morricone, who would then use his work in this film as an inspiration for the main theme in The Mercenary. Filming took place in Sierra de Órganos National Park in the town of Sombrerete, Mexico It was made as a co-production between France, Italy, Mexico, and the United States.