The observatory's sundial. Dengfeng Observatory, the oldest astronomical platform in China, is located in Gaocheng Village of Dengfeng township, Henan Province. It was built between 1267 to 1269 during the Yuan Dynasty. It was publically acknowledged for Cultural Heritage Protection by the State Council in 1961 and is purported to be one of the most ancient observatories in the world. The observatory displays ancient China's astronomical curiosity and innovation. On August 1, the observatory, as part of the Dengfeng "Center of Heaven and Earth," was added to the UNESCO World Heritage List. [Photo by Lin Liyao]