The stupas, or dagobas, were a form of structure specially erected for the purposes of Buddhist worship. They were sometimes built in the shape of a square tower upon rising ground, of which that at Sarnath, north of Benares, is the best known. The more important, however, are cylindrical and surmounted by a semicircular dome. These are usually erected on artificial mounds or tumuli, and are constructed either with jointed stones or with rough blocks bedded in cement. The interiors are of solid masonry, with the exception of a small square chamber, used as a repository for sacred emblems, the walls of which are continued up to the top of the dome. The stupa at Manikyala, is of great size, being upward of eighty feet in height, and measuring some three hundred feet in circumference. The base of the building is in the form of a cylinder, six or seven feet high, supporting an attic decorated with pilasters; above this the walls recede, and are capped by a hemispherical dome. There are a great number of dagobas in Ceylon, in the mountainous districts. They are usually placed in a walled enclosure, and surrounded by commemorative pillars. Smaller constructions of the same description are found in the interior of some of the temples, being placed where the baldachins, or altars, would be placed in Christian edifices. The rock temples of India are of two classes, the one consisting of grottos hollowed in the mountain side, and the other of a series of monolithic buildings cut bodily out of the solid rock, and detached from the surrounding hill plateaus by wide excavated areas. The former, resembling the speos of Egypt, consists of long galleries, divided into aisles by piers of the natural rock left at regular intervals to sustain the superincumbent mass. A recess or sanctuary is placed at one extremity, containing the statue of the divinity to whom the temple is dedicated. In some cases the interior is terminated by a semicircular apse with a hemispherical vault, and the entrance preceded by a vestibule containing votive figures, the whole forming a plan very similar to that of the Latin basilicas, which will be described in a subsequent chapter. The grottos are frequently excavated in several stories and connected by corridors and ramps.