There are twenty-five World Heritage Sites scattered across the United States. World Heritage Sites are the most important natural and cultural areas around the world; these are the places that the United Nations, and the 167 countries it represents, have recognized as the most important contributions to the heritage of humanity. World Heritage Sites are premier visitor destinations, yet most people are not familiar with the World Heritage Site designation and many of the places included on the World Heritage List. A Guide to America's World Heritage Sites: The Heritage of Humanity describes these twenty-five sites, including why they are so important, the visitor attractions they feature, and logistical advice on how to visit, appreciate, and protect them.