This keynote discussed the use of big data visual representation and semantic interpretation as tools to investigate complex urban dynamics in regions often resistant to conventional mapping and analytical methods. Focusing on Chinese-built stadiums across the Global South, the presentation examined these structures as instruments of architectural diplomacy and as catalysts of spatial, social, and environmental transformation. Between 1959 and 2022, China sponsored nearly 2,000 construction projects in developing nations — more than 150 of which were major sports facilities. While their architectural and typological features have been widely discussed, their urban and socio-spatial implications remain largely unexamined. The lecture demonstrated how the integration of Location- Based Social Network (LBSN) data, large-scale visualization, and AI-supported semantic analysis can reveal new dimensions of these infrastructures — uncovering how they attract flows of people, reshape patterns of urban movement, and influence local economies and communities. By merging data-driven interpretation with design thinking, the presentation proposed a new framework for understanding the geopolitical, ecological, and cultural agency of largescale architecture in the contemporary city.