structure as to cause it at a little distance to have all the appearance of a magnificent piece of mosaic.” [Illustration: Fig. 23.--Pueblo Building, restored.] [Illustration: Fig. 24.--Ground Plan of Pueblo Building.] Other ruins have been examined in this northern part of the old Mexican territory, and more will be brought to light, for the whole region has not been carefully examined, and new discoveries are constantly reported. CENTRAL MEXICO. As we go down into Central Mexico, the remains assume another character, and become more important; but the antiquities in this part of the country have not been very completely explored and described, the attention of explorers having been drawn more to the south. Some of them are well known, and it can be seen that to a large extent they are much older than the time of the Aztecs whom Cortez found in power. In the northern part of the Mexican Valley was the city of Tulha, the ancient capital of the Toltecs. At the time of the conquest its site was an extensive field of ruins. At Xochicalco, in the State of Mexico, is a remarkable pyramid, with a still more remarkable base. It was constructed with five stages or stories, and stands on a hill consisting chiefly of rock, which was excavated and hollowed for the construction of galleries and chambers. The opening serves as an entrance to several galleries, which are six feet high and paved with cement, their sides and ceilings seeming to have been covered with some very durable preparation which made them smooth and glistening. Captain Dupaix found the main gallery sixty yards, or one hundred and eighty feet long, terminating at two chambers which are separated only by two massive square pillars carefully fashioned of portions of the rock left for the purpose by the excavators. Over a part of the inner chamber, toward one corner, is a dome or cupola six feet in diameter at the base, and rather more in height. It has a regular slope, and was faced with square stones well prepared and admirably laid in cement. From the top went up a tube or circular aperture nine inches in diameter, which probably reached the open air or some point in the pyramid. In this part of Mexico can be seen, among other things, the great pyramid or mound of Cholulu, the very ancient and remarkable pyramidal structures at Teotihuacan, and an uncounted number of _teocallis_ or pyramids of smaller size. The pyramid of Cholulu covers an area of forty-five acres. It was terraced and built with four stages. When measured by Humboldt it was 1400 feet square at the base, and 160 feet high. At present it is a ruin, and, to superficial observers, seems little more than a huge artificial mound of earth. Its condition of decay indicates that it is much older than even the Toltec period. The largest structure at Teotihuacan covers eleven acres. These structures, and the Mexican _teocallis_ generally, were made of earth, and faced with brick or stone.