The novel and film specifically mention the following locations:
* The MacNeil Residence: The house where Regan, the possessed girl, lives with her mother, Chris. The house's address is given as 3600 Prospect Street, NW, but this address actually corresponds to the Georgetown Visitation Preparatory School.
* Georgetown University: The film features a scene where Father Damien Karras, the priest who becomes involved in the case, visits the university.
* The Georgetown Hospital: Regan is initially taken to the hospital for medical treatment before Father Damien seeks out Father Lankester Merrin, the Jesuit priest who performs the exorcism.
* The St. Albans School: This private all-boys school is briefly mentioned in the novel, as Father Damien's younger brother is a student there.
While the film uses real-life locations in Georgetown, it's important to remember that the story is fictional. The real-life locations are used as a backdrop for the fictional narrative.