This work investigates the urban morphology and spatial evolution of Cagliari (Karales) from its pre-urban foundations through the Roman, Late Antique, and Medieval periods, culminating in modern planning dynamics. Grounded in a comprehensive archaeological survey, the research synthesizes historical cartography, epigraphic sources, and material evidence to reconstruct the functional layout and territorial interactions of the ancient city. By examining key urban sectors—Stampace, Marina, and Santa Gilla—the study reveals the structural transformation from Punic settlement patterns to a monumental Republican and Imperial Roman municipal organization. Particular emphasis is placed on terraced sanctuary complexes, civic infrastructure, residential architecture, and suburban necropoles. Furthermore, the author establishes an operative framework that integrates the resulting archaeological risk map into contemporary urban planning instruments. Ultimately, this research bridges classical topography and spatial management, offering a diachronic model for preserving cultural heritage within living urban environments.