This thesis investigates how visualization strategies and media platforms affect citizen engagement with urban public data. There is currently an international movement towards government transparency and accessible information as developed nations become more urbanized and information technology more ubiquitous. Concurrently, new media platforms (e.g., virtual and augmented reality) are evolving rapidly and show promise of mass adoption. These factors together offer design researchers a unique opportunity to develop new forms of citizen-facing media. I therefore developed an interactive augmented reality application that works with a printed map of the city of Toronto to overlay open government data as visualized digital content. An iterative practice-based research approach was used. Usability tests demonstrated that a strength of augmented reality is its facilitation of multi-user engagement. This thesis concludes by discussing how the Toronto augmented reality map can be made into an interactive citizen-facing installation in the public sphere.