|Originally a simple elevation above the ground, made of earth, fieldstones, or turf; and such altars continued to be used in the country parts of Italy. But altars for constant use, especially in temple service, were, as a rule, of stone, though in exceptional cases they might be made of other materials. Thus, several in Greece were built out of the ashes of burnt-offerings, as that of Zeus at Olympia. One at Delos was made of goats' horns. Their shape was very various, the four-cornered being the commonest, and the round less usual. A temple usually had two altars: the one used for bloodless offerings standing before the deity's image in the cella, and the other for burnt-offerings, opposite the door in front of the temple. The latter was generally a high altar, standing on a platform which is cut into steps. Being an integral part of the whole set of buildings, its shape and size were regulated by their proportions. Some few of these high altars were of enormous dimensions; the one at Olympia had a platform measuring more than 125 feet round, while the altar itself, which was ascended by steps, was nearly 25 feet high. In Italy as well as Greece, beside the altars attached to temples, there was a vast number in streets and squares, in the courts of houses (see cut), in open fields, in sacred groves, and other precincts consecrated to the gods. Some altars, like some temples, were dedicated to more than one deity; we even hear of altars dedicated to all the gods. On altars to heroes, see HEROES.