Buddhist religious architecture developed in the Indian subcontinent. Three types of structures are associated with the religious architecture of early Buddhism: monasteries (viharas), places to venerate relics (stupas), and shrines or prayer halls (chaityas, also called chaitya grihas), which later came to be called temples in some places. The initial function of a stupa was the veneration and safe-guarding of the relics of Gautama Buddha. The earliest archaeologically known example of a stupa is the relic stupa located in Vaishali, Bihar in India. In accordance with changes in religious practice, stupas were gradually incorporated into chaitya-grihas (prayer halls). These are exemplified by the complexes of the Ajanta Caves and the Ellora Caves (Maharashtra). The Mahabodhi Temple at Bodh Gaya in Bihar is another well-known example. The pagoda is an evolution of the Indian stupas. Buddhist temple architecture Architecture of Indic religions Ancient Indian architecture Vastu shastra and Shilpa Shastras A characteristic new development at Buddhist religious sites was the stupa. Stupas were originally more sculpture than building, essentially markers of some holy site or commemorating a holy man who lived there. Later forms are more elaborate and also in many cases refer back to the Mount Meru model. One of the earliest Buddhist sites still in existence is at Sanchi, India, and this is centred on a stupa said to have been built by King Ashoka (273–236 BCE). The original simple structure is encased in a later, more decorative one, and over two centuries the whole site was elaborated upon. The four cardinal points are marked by elaborate stone gateways. As with Buddhist art, architecture followed the spread of Buddhism throughout south and east Asia and it was the early Indian models that served as a first reference point, even though Buddhism virtually disappeared from India itself in the 10th century. Decoration of Buddhist sites became steadily more elaborate through the last two centuries BCE, with the introduction of tablets and friezes, including human figures, particularly on stupas.