What are the pros and cons of world heritage sites?

"The United Nations Educational, Scientific and Cultural Organization (UNESCO) seeks to encourage the identification, protection and preservation of cultural and natural heritage around the world considered to be of outstanding value to humanity. This is embodied in an international treaty called the Convention concerning the Protection of the World Cultural and Natural Heritage, adopted by UNESCO in 1972," per http://whc.unesco.org/en/about/ While the goal of the UNESCO World Heritage Site project is to recognize and protect significant sites worldwide, most parks benefit only in increased recognition and worldwide awareness as a place of importance. Unless a park or preserve is established the World Heritage Fund monies that would not otherwise be established, the designation as a UNESCO World Heritage Site is mostly a feather in the cap for sites that are already protected. Some people believe, wrongly, that U.S. National Parks that are designated as World Heritage Sites are being "taken over" by the United Nations. Quite on the contrary, the UN has no bearing on how US National Parks are managed and parks seek the designation mainly for publicity.