Everyone, this is a comparison picture of the restoration of the Fengxian Temple Buddha in Longmen Grottoes in the 1970s before and after. At that time, the surface of the Buddha was cracked and loose, and 20 anchor rods were reinforced on the surface and sides of the main statue, which had a good effect. We now see that the overall condition of Fengxian Temple is after reinforcement at that time... "Not far from Longmen Grottoes, a forum focusing on" protection, inheritance, and value dissemination of grotto temples "was lively. Experts and scholars from China and abroad gathered at the 2025 International Forum on the Protection of Grotto Temples to contribute their experience and achievements to the sustainable development of grotto temples from their respective research fields. Ma Chaolong, Deputy Director of the Grottoes Protection Research and Heritage Monitoring Center of Longmen Grottoes Research Institute, introduced to everyone at the forum the decades long practice of protection. From solving the stability problem of grottoes, to crack sealing, grouting reinforcement to solve the problem of water leakage, and now to the orderly construction of daily maintenance, environmental improvement, and monitoring system, the path of protection has been taken step by step. This is also a necessary path that nearly 6000 existing grotto temples and cliff sculptures in China have experienced or are currently experiencing. Currently, the protection of Chinese grotto temples is undergoing a leapfrog development stage from salvage protection to preventive protection. ”Fan Jinshi, Honorary Dean of Dunhuang Academy, pointed out. Specifically, in the past we only focused on conservation engineering, but now we are developing towards scientific research throughout the entire process; In the past, only attention was paid to the safety of cultural relics, but now they are comprehensively protected along with their environment; In the past, the focus was on the protection of domestic grottoes, but now it is gradually opening up an international perspective... Taking monitoring methods as an example, Li Li, Vice President of the Chinese Academy of Cultural Heritage, said that traditional monitoring includes the detection of grotto safety, protection scope, monitoring area, as well as the detection of the overall environment, small environment, and micro environment of grottoes. Today, a diverse and multi-scale monitoring system for the protection of grottoes has gradually formed. At the North Grottoes Temple in Qingyang, Gansu, three years ago, we used advanced technology to monitor the entire mountain and area where the grottoes are located, achieving authenticity protection and dynamic protection, as well as overall protection of the body and dependent environment. ”Li Li believes that these protection concepts have reached industry consensus. The concept of cultural relic protection in our country originates from traditional culture. Liang Sicheng, an architect, put forward the idea of "if there is something, if there is nothing, if there is truth, if there is wisdom, if there is ignorance" to reinforce the cliff body of the Mogao Grottoes of Dunhuang, emphasizing that the restoration does not change the original state of the cultural relics, which is a typical representative. Since the beginning of the 21st century, based on fully absorbing advanced concepts of international cultural heritage protection, China has carried out a large number of theoretical and practical innovations in cultural heritage protection. The "Guidelines for the Protection of Chinese Cultural Relics and Monuments" have emerged, experiencing an expansion from "cultural relics" to "cultural heritage", from "repairing the old as it is" and "not changing the original state" to "minimal intervention" and a shift in emphasis on protecting historical environment and values. How to do preventive protection well? Su Bomin, the director of Dunhuang Academy, brought new practical practices. There are isolation doors outside the caves of Mogao Grottoes, creating a difference between the internal and external environment and providing protection. Research has found that the airtightness and ventilation of this door have a significant impact on the microenvironment. Therefore, researchers have conducted a series of studies and modifications on the isolation door, and have developed a model door. Now, we have installed it in Xiqianfo Cave and after a year of testing, the effect is very good. Preventive protection should be implemented through specific measures. ”Su Bomin said. The Yungang Grottoes that people see today have gone through 1500 years of vicissitudes. However, most of the current research data comes from the detection and monitoring of weathering in grottoes over the past two to three decades. Can we understand how grottoes have come to be today on a longer time scale? Understanding the past weathering process is extremely important for predicting the future development of cave weathering. The research idea of Huang Jizhong, Dean of the School of Cultural Heritage and Information Management at Shanghai University, is to sort out the historical images of Yungang Grottoes in different periods over the past century, and based on this, design a deep learning framework to achieve automatic recognition of typical weathering features based on cultural relics historical images. Through the comparison of images from 1939 and 2019, we found that the issue of cracks outside the repair area still requires special attention; The clarity of carved textures has decreased significantly, but weathering is still very fast. ”Huang Jizhong said. Natural disasters are also a test of the thousand year standing of grotto temples. The director of the Japan Cultural Heritage Disaster Prevention Center, Yoko Takahashi, suggested that the restoration of historical relics damaged by disasters should also be considered from the perspective of disaster reduction. Even if a decision is made not to intervene to maintain the authenticity of cultural heritage, it is necessary to consider arranging measures to mitigate damage in the event of future disasters, so that they can be more resilient to disasters after the disaster than before. While protecting the essence, more and more grotto cultural relics are achieving "digital immortality". The massive digital achievements of "Digital Dunhuang Resource Library" and "Digital Sutra Cave" of the Dunhuang Research Institute were launched online. The Longmen Grottoes Research Institute successfully repaired the collapsed eaves of the grottoes by 3D printing, and the Dazu Rock Carvings Research Institute presented the stone sculptures in the digital world through real scene scanning and fine modeling... The charm of traditional culture is reborn in the modern context, and the millennium treasure "is in the cloud" forever. Through continuous innovation, open cooperation, and joint efforts of the whole society, we will promote the inheritance and revitalization of the cultural heritage of grotto temples in contemporary society, and contribute wisdom and strength to the progress of human civilization. ”Xie Bing, deputy director of the National Cutural Heritage Administration, said. (New Society)