WBEZ brings you unbiased news and information. Sign up for our newsletters to stay up to date on the stories that matter.UNESCO World Heritage sites aim to help preserve the world’s cultural and natural heritage. The Nixon administration first proposed the World Heritage Convention in 1972, but these days World Heritage Sites have wider recognition in other countries. The U.S. has fewer sites than Mexico, China or Russia. Phyllis M. Ellin, a historian from the National Park Service, joins us to discuss why that’s the case. (Photo: Wikimedia Commons).