The “port-city heritage” has recently gained more scholarly and professional attention. Yet, many questions remain in terms of terminology, characteristics, constituents or applicability of such a group of heritage objects. Understanding and defining the port city terms is crucial as it is intimately connected to what citizens and institutions deem valuable and choose to preserve. This article serves as the first step towards developing a shared vocabulary, as the foundation for a better understanding of specific values or identities inherent in port cities. In the world heritage list, we identified 107 sites related to port city. By decoding and analyzing the short abstracts of these sites with a systematic approach, we tried to understand how UNESCO conceptualize port-city heritage, how UNESCO acknowledge the value of port-city heritage sites, what the problematic issues are in this conceptualization and why, and how the historical urban landscape approach can contextualize the sites in larger networks and flows. Findings indicate the port-city heritage conceptualized by UNESCO is focused very much on local contexts, and of OUV that are mostly related to the military, trading and colonial practices. We argue such limited vision on the valuing of port-city heritage impair the understanding of complex linkages between nature and culture, one port-city and another, global and local values, and after all the systematic thinking of port-city-region as a networked entity.