This article explores the innovative deployment of the "Urban Data Mural" as a participatory design tool in urban sustainability research. Situated within the framework of open science, the project facilitates a dynamic interaction among urban data stakeholders—territorial managers, scientists, and citizens. The mural serves as a platform for these actors to engage directly with data production and utilization processes, thereby addressing common challenges such as data accessibility, comprehension, and origin awareness. Through workshops and collaborative activities, the mural integrates diverse data types—from open data provided by major platforms to sensitive data from research and government sources—into a cohesive system that supports urban planning and policy-making. This approach not only democratizes data access but also enhances stakeholder understanding and contribution to urban sustainability efforts.