The question of how Romans understood the world around them has inspired vigorous debate. In one camp, some argue that, due to a dearth of cartographic evidence and the prevalence of written itineraries, only linear understandings of space were possible, while others argue for the possibility of map-conscious, cartographic understandings. My project brings new evidence to this debate, in the form of floor mosaics with landscape and geographic imagery, to demonstrate that cartographic understandings of space were possible and wide-ranging. These mosaics display varied places like labeled Mediterranean islands, wild hunting grounds, and the Christian Holy Land. They compress large landscapes and geographies into their relatively small interiors, making their rooms microcosms of the world out there. I explore case studies organized thematically, compiling mosaics depicting water, land, map-like depictions, allegorical representations of space, and finally combinations of those types in a single Sicilian villa. Using theories of space and place and phenomenology, I study closely both the iconography and the archaeological contexts of the mosaics, situating these microcosmic floors back in their original spaces. I assess their scales relative to the human body, possible routes around their imagery, and views at downward angles. Often understudied as physical floors, I show how the mosaics allowed their viewers to inhabit and engage with the microcosms they created, physically imparting or reinforcing particular understandings of the expanses they depict. I conclude that because most of these floors depict geographically specific and even labeled places, as well as faraway places, and because the majority of the floors were laid down well after the establishment of the Roman empire, they can reveal increased cartographic understandings of the world that came with Rome’s imperial project. Several important ideas about empire emerge, like connection across the Roman world and access to its many landscapes and resources. Compressing these landscapes and geographies, owning or funding them, and making them accessible to others could be a clear way for Romans to show power.