Grottoes are an outdoor art museum of stone carvings and have significant value. The Longmen Grottoes near Luoyang (Henan Province), the Mogao Caves near Dunhuang (Gansu Province) and the Yungang Grottoes near Datong(Shanxi Province), are known as the three greatest stone sculpture treasure houses in China. They vividly record the culture of Buddhism, which is a very important religion in China and one of the three major schools of thought along with Confucianism and Taoism. The three noted grottoes also reflect political, economic, and cultural states in ancient China. They give us historical data for the researching of ancient religion, arts, architecture, calligraphy, music, dress, and medicine, and can be called a large scale stone-carved art museum.