While many geographical studies analyze the real city as a quasi-virtual object which can only be measured in terms of statistical data and pixels, it can be salutary to treat an imaginary city as a real object, whose space is both lived and perceived by fictional characters.This is the case of The Line, which will be built in the Neom (Neo-Mustaqbal or New Future) perimeter, in northwestern Saudi Arabia (Figure 1) - an area chosen in 2016 by Crown Prince Mohamed Ben Salmane to become the embodiment of a major national transformation and modernization project known as Saudi Vision 2030.Yet, even if one chooses a "real" field, to what "reality" can the investigation lay claim (Musset, 2018)? In his work on cities in modern France, Bernard Lepetit has highlighted the need for the historian to put himself in the place of contemporaries in order to try to understand patterns of representation that are no longer ours because they obey categories that have evolved over time (Lepetit, 1988a). He has also shown that it is vain to look for a perfect adequacy between the historical analysis and its object, invoking both Magritte's painting which proclaims "This is not a pipe" (and for good reason, since it is only the representation of a pipe), and Zeno's paradox, whose theoretical arrow will never reach its target because it has to pass through all the points of a straight line composed of an infinite number of points (Lepetit, 1988b).