The four completed "chaitya" halls are caves 9 and 10 from the early period, and caves 19 and 26 from the later period of construction. All follow the typical form found elsewhere, with high ceilings and a central "nave" leading to the stupa, which is near the back, but allows walking behind it, as walking around stupas was (and remains) a common element of Buddhist worship ("pradakshina"). The later two have high ribbed roofs carved into the rock, which reflect timber forms, and the earlier two are thought to have used actual timber ribs and are now smooth, the original wood presumed to have perished. The two later halls have a rather unusual arrangement (also found in Cave 10 at Ellora) where the stupa is fronted by a large relief sculpture of the Buddha, standing in Cave 19 and seated in Cave 26. Cave 29 is a late and very incomplete "chaitya" hall.