This book investigates the hidden physical infrastructures behind the digital world. Data may appear immaterial, but it relies on extensive global networks: the extraction of raw materials, the deployment of thousands of undersea cables, and an exponentially growing number of energy-intensive data centers. While these data infrastructures shape global economies and politics, they truly do far more by profoundly impacting local communities, ecosystems, and labor conditions-realms so often rooted in (neo)colonial structures of exploitation. The contributions in this volume call for greater transparency, critical awareness, and care toward the material foundations of the data economy-as essential conditions for more equitable and accountable digital futures. Bringing together voices from architecture, media studies, technology, art, and political theory, City in the Cloud - Data on the Ground explores the elemental, spatial, and temporal dimensions of the architecture of data. The volume maps the costs of the data economy-ecological, social, and political-and opens up perspectives for rethinking digital infrastructures in the context of planetary resources, justice, and long-term responsibility.