Angkor, a world cultural heritage site in Cambodia, has a very important role in architectural history. This is a very large, well-protected site and has great value in history, art and science. This paper describes studies of the architectural and structural forms of the Angkor Grottoes from the perspective of civil engineering. Based on on-site investigations, the main types of damage to the grottoes result from structural destruction and material destruction were determined. Different technologies, based on the type of destruction, should be used in conservation.