Though the Maya did not for the most part use large masses of stone for building, yet they were able to handle monoliths of considerable size, as may be seen from the number of carved stelæ which constitute so important a feature of many of the ruined sites. These stelæ consist of monolithic pillars, approximately rectangular and decorated with relief carving, usually on all sides. The largest of these are found at Quirigua, but the art of the neighbouring site of Copan (Pl. XXI; p. 236) is the finer, since many of the stelæ here are carved in such bold relief as to approximate to sculpture in the round. At these two sites most of the stelæ present on their principal faces a human or divine figure, usually represented _en face_, and holding the sky-bar (occasionally replaced at Quirigua by the ceremonial axe). At Tikal, Naranjo (Pl. XXIII; p. 302), and Menché (Pl. XXII; p. 294) the relief is less bold, and the figures are usually therefore shown in profile, at any rate as far as the face is concerned. At Seibal and Piedras Negras profile figures predominate, but a few occur shown _en face_ (Pl. XX; p. 224), among them the figures seated in niches already mentioned as characteristic of the latter locality. At Palenque only one stela has been found, but on the other hand comparatively little stone-carving occurs here, though the deficiency is amply supplied by the quality of the magnificent mural tablets in relief which constitute the chief feature of the site. The sky-bar does not appear on the stelæ of Piedras Negras, though the ceremonial axe is occasionally seen. Both emblems occur at Naranjo, Tikal, Seibal and Menché. A few stelæ have been found in Yucatan, e.g. at Sayil; but they are confined to the northern portion of the district and even here are rare and poorly carved. The exact purpose of the stelæ is problematical. In the large majority of cases they stand in definite relation to certain buildings, in fact all at Naranjo, Seibal, Menché and Piedras Negras are connected with temples. At Copan and Quirigua some appear to be independent. They are usually found situated in the courts, though at Piedras Negras a series exists arranged along the lower terrace of a foundation-mound. Many are furnished with altars in front of them (Fig. 81), and they appear to have been the objects of some cult. A most important point in connection with them lies in the fact that so many of them bear dates in the long count as described in chapter X, and this fact, combined with the statements of early authors that the historical Maya were wont to mark the passage of a katun by setting up a “stone,” lends colour to the opinion that the early Maya followed a similar practice. Many of the dates mark quarter katuns, but many again do not, and though we may conclude that they were in some way commemorative monuments, it is impossible at present to define their use more exactly. As stated before, many of the stelæ were