In light of a functional interest in natural systems in cities, this article suggests using a landscape perspective approach and analysis. Its objective is to recognize nature as the origin and structure of urban landscape. To do so, we propose an Index of Connections between Cities and Nature (ICCN), which compares the potential of the natural-landscape substrate with how much it is used during the urban experience. The ICCN is applied to nine cities around the world, and the results are analyzed. Finally, using Medellin as an example, we offer support to those who want to recover the natural foundations of their cities to make them more efficient, enjoyable, and authentic.