Crowds on the Great Wall of China. One of the world's most famous monuments, the Great Wall is visited by large numbers of tourists each year. In sites with so many visitors, the sheer number of people, combined with the pressure for commercial development, can threaten both the monument itself and the surrounding landscape. To better preserve heritage sites in China, the country's State Administration for Cultural Heritage and the GCI—with the Australian Heritage Commission—have collaborated to develop and promote national guidelines for site conservation and management. Photo: Guillermo Aldana.