Abstract:On the platform of Tuancheng in Beijing, there are several ancient pines, said to be relics of Liao and Jin dynasties. Emperor Qianlong of the Qing Dynasty conferred titles on three ancient trees. More than 10 years ago, when Tuancheng was being renovated, a worker in the construction team piled quicklime around a pine tree named "Tanhai Hou". The quicklime evaporated and the ancient tree died.