Cliff dwellings in Mesa Verde National Park in Colorado
Cliff dwellings in Mesa Verde National Park in Colorado (© Brad McGinley Photography/Getty Images)
A 50-year balancing act
At its World Heritage Convention on November 16, 1972, UNESCO adopted an international treaty that for the first time linked the concepts of nature conservation and preservation of cultural properties. The World Heritage Sites program was sparked by Egypt's planned construction of the Aswan High Dam, which would have flooded a large swath of the Nile Valley and thousands of archeological treasures.
© Brad McGinley Photography/Getty Images