Abstract: As smart-city development moves from strategic design to implementation, the intelligence of urban spaces is becoming a critical means of realizing smart-city visions. Drawing on 246 iSpace projects completed or under construction worldwide over the past decade, this study reviews the current state of practice. Integrating this evidence with theoretical research, it defines iSpace as an urban setting in which advanced technologies enable the sensing of user needs and environmental conditions, informed decisionmaking, adaptive responses, and continual learning and optimization. iSpace has two defining attributes - technological enablement and a spatial carrier - and four planning elements: comprehensive perception, precise judgment, appropriate response, and learning-based optimization. The paper further proposes actionable pathways for the intelligent transformation of urban spaces, offering a theoretical framework and practical guidance for wider implementation.