The present contribution examines the interplay between settlement expansion and metropolitan landscapes, focusing on the emergence and significance of urban voids at both local and regional scale. Adopting a transdisciplinary approach, it integrates architectural, geographical, social, and environmental perspectives to analyze the evolution of dispersed urban forms, peri-urban territories, and the spatial distribution of vacant land. Urban voids—intended as areas left vacant by obsolescence, abandonment, or shifts in final use—are interpreted as relational spaces with morphological, functional, social, and ecological value, serving as connective tissue within cities. This work proposes multi-criteria analytical frameworks, operational tools and visual experiences, for the sustainable management and valorization of urban voids, emphasizing the potential of these spaces to support social life, environmental restoration, and cohesive metropolitan landscapes. It argues for landscape-sensitive, interdisciplinary planning strategies that reconceptualize vacant land from residual byproduct of urban growth into multifunctional, resilient, and socially inclusive assets fostering sustainable metropolitan development.