Buddhist religious architecture developed in the Indian Subcontinent in the 3rd century BCE.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.Viharas initially were only temporary shelters used by wandering monks during the rainy season, but later were developed to accommodate the growing and increasingly formalised Buddhist monasticism.