In recent years, the world witnessed the rise of big digital platforms like Amazon, Airbnb, and Uber. The emerging research field of platform urbanism focuses on these developments and concentrates on platforms and their impact on everyday life in urban space. This book introduces a novel approach to the problems of accessibility and opacity in this area of research. In order to explore the black box platform urbanism more thoroughly, different participatory mapping approaches of critical cartography are examined. The potential of so-called counter-mapping practices and related approaches for a deeper exploration of platform urbanism is discussed. The author thus establishes the nexus between participatory mapping approaches of critical cartography and their application potential for platform urbanism and provides numerous starting points for future research.