The religion Buddhism became the principal religion of India around the 2nd to 3rd century BC. In this era, stone was also introduced for the first time in Indian art and architecture. The Buddhist Stupas are supposed to be much older than the Hindu temples. The Stupas are mound-shaped and  preserve the relics either of the Buddha or of a great figure of the Buddhist church. Since the Stupas are  identified with the subtle body of the Buddha, so they are comparable to a temple. In the initial stage, the stupa evolved into an elaborate structure with beautiful sculpture enhancing the encircling balustrades and the gateways. The Stupa at Sanchi is one of the finest and impressive example of the sculptures, that belongs to the 3rd century BC. Incidents from the life of Buddha are illustrated together with the various deities of the folk religion.

Another artistic achievement of this period is the famous stupa at Sanchi. In every stupa there was a small camber in which a casket with relics of the Buddha or the Buddhist monks were placed. The surface of the stupa was generally built of bricks with a thick layer of plaster. The stupa was crowned by an umbrella of stone. The monument was surrounded by a fence with a path provided for Pradakshina (circumambulation). The original stupas were enlarged and beautified from time to time. The Sanchi stupa which still stands intact is a well-preserved and splendid monument. A number of lesser stupas and other buildings such as monasteries and rest-houses are found in and around the main stupa.

The stupa at Sanchi as it stands today has stone railings and gateways around it. These were added later after the Mauryas. The gateways are a very striking feature. There are four gateways at the four cardinal points and they contain very lively and beautifully carved panels. In these panels are depicted events from the life of the Buddha and details from the Jataka stories. They also depict a landscape of trees and floral designs, groups of animals and birds, beautiful figures of yakshas and yakshinis, and men and women. Thus the Sanchi reliefs present the story of the Buddha and provide glimpses into Indian life through clear, simple and dramatic scenes. 
The Buddha is depicted in these panels not through his image but through the use of various symbols; for example, the horse represents his ‘renunciation’, the ‘boddhi’ tree his enlightenment.