The study of the genre of urban fantasy presents a unique opportunity to study how the city is conceptualized. Most critical work, however, has focused on spatial possibilities of imaginary cities, rather than investigating the differences between real life cities and their fantastical versions. This thesis examines contemporary urban fantasy about Chicago in particular, a city unique in its tendency towards realism in literary and cultural production, and in the influence of the Chicago school of Urban Sociology, which pioneered mapping of urban spaces and processes. This investigation focuses specifically on the question of mappability within The Time Traveler’s Wife by Audrey Niffenegger and My Favorite Thing is Monsters, by Emil Ferris. In The Time Traveler’s Wife, I examine the characters’ attempt to nostalgically reappropriate urban space in the face of passing time by remapping the city, drawing on the ideas of Svetlana Boym and Michel de Certeau. My Favorite Thing is Monsters, by contrast, finds sanctuary rather than terror in the unmappable parts of the city, looking for possibilities for marginalized groups in the liminal spaces between the real and the imaginary. Both works, in setting their stories in the real-world city of Chicago, comment on the fantastical possibilities of the city itself and the danger–and joy–of the unknown.