In response to the national call to promote China's excellent traditional culture and enhance cultural confidence, 700 years ago Guo Shoujing did something that shocked the world: he accurately calculated the length of a year, 300 years earlier than Europe. He dredged the Tonghui River and unblocked Beijing's water veins; he built the Jianyi instrument, leading the world by 300 years; and he presided over the Four Seas Survey, extending observation points from Siberia to the South China Sea.