Anderson first saw Dano in "The Ballad of Jack and Rose" and thought that he would be perfect to play Paul Sunday, a role he originally envisioned to be a 12- or 13-year-old boy. Dano only had four days to prepare for the much larger role of Eli Sunday, but he researched the time period that the film is set in as well as evangelical preachers. The previous two weeks of scenes with Sunday and Plainview had to be re-shot with Dano instead of O'Neill. The interior mansion scenes were filmed at the Greystone Mansion in Beverly Hills, the former real-life home of Edward Doheny Jr., a gift from his father, Edward Doheny. Scenes filmed at Greystone involved the careful renovation of the basement's two-lane bowling alley. Anderson said it was "a particular situation, because it was so narrow that there could only be a very limited number of people at any given time, maybe five or six behind the camera and then the two boys."