This article aims to challenge the widespread consensus that Rio de Janeiro is a divided city by deploying two concepts in critical cartography: cartographic silences and cartographic calculations. As a kind of unconquered territory, a terrae incognitae, favelas were silenced on many of Rio de Janerio's maps over the last century. When these places began to be mapped, and converted to terrae cognitae, power relations often become even more apparent because of the intention to make it legible for purposes of intervention. By analyzing maps published in the mainstream Brazilian press throughout the last century, this article explores how national press often portrays Rio de Janeiro as a city divided between formal neighborhoods, where the state apparatus can ensure the rule of law, and favelas, where parallel politics enforce local forms of governance. In order to disseminate this image of the city, maps can play an important role, locating different urban zones and reinforcing old stereotypes. Despite many studies that focused on both material and embodied forms of state presence within favelas, maps can be an important source of information to understand persistant representations of favelas as excluded and divided places.