A chaitya is a Buddhist or Jain shrine including a stupa . In modern texts on Indian architecture, the term chaitya-griha is often used to denote assembly or prayer hall that houses a stupa. Architecturally they show similarities to Roman design concepts of column and arch.
The chaitya-griha at Bhaja Caves was constructed in the first century BCE. It consisted of an apsidal hall with stupa. The columns sloped inwards in the imitation of wooden columns that would have been structurally necessary to keep a roof up. The ceiling was barrel-vaulted with wooden ribs set into them. The walls were polished in the Mauryan style. It was faced by a substantial wooden facade. A large horseshoe-shaped window, the chaitya-window, was set above the arched doorway and the whole portico-area was carved to imitate a multi-storeyed building with balconies and windows and sculptured men and women who observed the scene below. This created the appearance of an ancient Indian mansion (Dehejia 1997).
In Bhaja, as in other chatya-grihas, the entrance acted as the demarcation between the sacred and the profane. The stupa inside the hall was now completely removed from the sight of anyone outside. In this context, in the first century CE, the earlier veneration of the stupa now changed to the veneration of an image of the Buddha. Chaitya-grihas were commonly part of a monastic complex, the vihara.