A chaitya, chaitya hall, chaitya-griha, (Sanskrit:Caitya; Pāli: Cetiya) refers to a shrine, sanctuary, temple or prayer hall in Indian religions. The term is most common in Buddhism, where it refers to a space with a stupa and a rounded apse at the end opposite the entrance, and a high roof with a rounded profile. Strictly speaking, the chaitya is the stupa itself, and the Indian buildings are chaitya halls, but this distinction is often not observed. Outside India, the term is used by Buddhists for local styles of small stupa-like monuments in Nepal, Cambodia, Indonesia and elsewhere. In Thailand a stupa, not a stupa hall, is called a chedi. In the historical texts of Jainism and Hinduism, including those relating to architecture, chaitya refers to a temple, sanctuary or any sacred monument. Most early examples of chaitya that survive are Indian rock-cut architecture. Scholars agree that the standard form follows a tradition of free-standing halls made of wood and other plant materials, none of which has survived. The curving ribbed ceilings imitate timber construction. In the earlier examples, timber was used decoratively, with wooden ribs added to stone roofs. At the Bhaja Caves and the "Great Chaitya" of the Karla Caves, the original timber ribs survive; elsewhere marks on the ceiling show where they once were. Later, these ribs were rock-cut. Often, elements in wood, such as screens, porches, and balconies, were added to stone structures. The surviving examples are similar in their broad layout, though the design evolved over the centuries. The halls are high and long, but rather narrow. At the far end stands the stupa, which is the focus of devotion. Parikrama, the act of circumambulating or walking around the stupa, was an important ritual and devotional practice, and there is always clear space to allow this. The end of the hall is thus rounded, like the apse in Western architecture. There are always columns along the side walls, going up to the start of the curved roof, and a passage behind the columns, creating aisles and a central nave, and allowing ritual circumambulation or pradakhshina, either immediately around the stupa, or around the passage behind the columns. On the outside, there is a porch, often very elaborately decorated, a relatively low entranceway, and above this often a gallery. The only natural light, apart from a little from the entrance way, comes from a large horseshoe-shaped window