Dr Caligari has really wonderful sets that add to the surreal quality of the film and evoke a sort of eeriness that would not have been as powerful without them. The painted on shadows create a patchiness to the scenes as though, even indoors and during the day, they are foreshadowing some kind of danger for the characters. On another level it also implies that the "reality" of the action is not, in fact, reality, but a dream conjured up by the main character. The windows and doors are not rectangular and are so surreal that watching the movie is similar to a tour through the Dali museum. This surreality makes the viewer think. Is the whole story true, or is the main character actually insane and his whole tale is the delusion he lives in, like Shutter Island? One of the best aspects is that it leaves this question unanswered. We have the choice whether to believe in the Director, or Dr Caligari.