Do you know that just like people's health check-up with ultrasound, CT, and other methods, ancient buildings also have their "health check-up"? Zhang Tao, the "cultural relic doctor", is mainly engaged in the preventive protection of ancient buildings, that is, to carry out preventive treatment for cultural relics. Along the Beijing Central Axis, heritage sites such as Wanning Bridge, Jingshan Hill, and Yongdingmen are all within the range of their examinations. Unlike the old masters who rely