This study critically examines contemporary architecture with the hypothesis that it largely overlooks the needs of children. It argues that architecture has evolved since the earliest civilizations to address the needs and visions of adults, often excluding considerations for children. Architectural knowledge is predominantly shaped by adult perspectives, which influence how architecture is studied, applied, and developed to meet architects’ visions and design requirements. As a result, children are relegated to mere users of the built environment. The paper specifically focuses on outdoor design to explore these issues. It traces the historical development of outdoor spaces from ancient civilizations to the present, highlighting how cities have traditionally been designed according to adults’ spatial understanding and needs, rather than those of children. The study evaluates urban livability for children through case studies in Oslo, Norway, and Riyadh, Saudi Arabia, examining the current state of outdoor spaces in modern cities. The study’s contribution lies in emphasizing that architecture is primarily tailored to adults and advocating for the development of architectural knowledge that fully integrates children’s needs in all aspects of architectural thinking and design. This approach calls for further research into methods of incorporating children’s needs into architectural practice. Special thanks to my students Majed Binabbas and Faisal Alshammary, and Faisal Alsabeg in Alfaisal university, Riyadh, Saudi Arabia, for assisting with case studies of Riyadh, Saudi Arabia. Special thanks to Architect Jean Nooraddin, Suzan Nooraddin, and Aya Nooraddin at American University of Dubai for assisting with case studies of Oslo, Norway. Many thanks to Professor Einar Lillebye at Cities Architecture for Children organization in Norway for his productive discussions about the topic.