Maritime and land transportation modes play a vital role in the growth of urban places and the distribution of resources. In particular, port terminals and road infrastructures connect urban areas in different scales, from local to global regions, because they share common characteristics in order to avoid geographical discontinuities. However, modeling spatial networks and analyzing their statistical attributes is not trivial because there is little agreement among disciplines on a common framework. This chapter presents a geometric graph where ports and cities were connected by road infrastructures to show the interplay between maritime, land, and urban systems. The inclusion of ports in a spatial system of cities connected by road networks complements economic geography applications to the complex networks approach. The planar graph displays significant geometric attributes to define and model a system of spatial objects. Such attributes help to identify valuable port locations based on their route distance to cities without extra information, for example statistical freight data.