The strategy of promoting culture through city image is strongly related to UNESCO strategy to develop particular cities through their World Heritage Program. This research focuses on heritage infrastructure and the entanglement with cultural investment, which are based in specific buildings commonly constituted as highly cultural valuable assets. This research takes two independent case studies to compare the demographic, economic and social effects on Valparaíso, Chile and Hoy An, Vietnam after their nomination as a World Heritage Site. The results on both cities are contrasted analysing the slots distribution of the heritage sites and their activity before and after the nomination. The findings of this study show that the nomination´s positive effects on tourism depend on the empowerment of the local government to manage the heritage site; additionally, it is restricted to the political context of each country. Therefore, the nomination by UNESCO does not guarantee a positive contribution in terms of city branding. On the contrary, an inefficient administration of the heritage site can originate an overexploitation of the site and a redistribution of the demographic characteristics. In the end, the nomination for World Heritage Site not only represents touristic benefits for the city but also holds complex responsibilities on the strategy to sell the city/town brand. It appears that recognizing the global plan of the UNESCO World Heritage Site in a national and local sphere context is the most effective way to transmit an authentic experience for the tourists, ensure the sustainability of the cultural investment and respect the interests of the local community.