Some of the great edifices in these old ruins, such as the “Palace” at Palenque, and the “Casa del Gobernador” at Uxmal, remind us of the “communal buildings” of the Pueblos, and yet there is a wide difference between them. They are not alike either in character or purpose, although such great buildings as the “Palace” may have been designed for the occupation of several families. There is no indication that “communal” residences were ever common in this part of the country. At the time of the Conquest the houses of the people were ordinary family dwellings, made of wood, and we may reasonably suppose this fashion of building was handed down from the earlier ages. Herrera, who supposed, mistakenly, that all the great stone edifices were temples, said, in his account of Yucatan, “There were so many and such stately stone buildings that it was amazing; and the greatest wonder was that, having no use of any metal, they were able to raise such structures, which seem to have been temples; for their houses were all of timber, and thatched.” But they had the use of metals, and they had the art of making some of them admirable for use in cutting stone and carving wood. [Illustration: Fig. 48.--Watch-tower at Tuloom.] Among the buildings of later date are some of those on the western coast, which were still inhabited three hundred and fifty years ago. The city of Tuloom was inhabited then. Figure 47 shows a ground plan of the walls of this city, with the position of some of the ruined monuments. Within the walls are remains of finely constructed buildings on elevated foundations, none of them, however, very large. One of them had a wooden roof, and timber seems to have been considerably used here. The walls still standing were made of hewn stone. Remains of stone edifices exist all along this coast, but the whole region is now covered by a dense growth of trees and other vegetation. Tuloom was seen in 1518 by Grijalva, who sailed along the coast. At that time the island of Cozumel, where noteworthy ruins are found, was inhabited by many people. Figure 48 shows one of the watch-towers on the walls of Tuloom. VI. ANTIQUITY OF THE RUINS. The Mexican and Central American ruins make it certain that in ancient times an important civilization existed in that part of the continent, which must have begun at a remote period in the past. If they have any significance, this must be accepted as an ascertained fact. A large proportion of them had been forgotten in the forests, or become mythical and mysterious, long before the arrival of the Spaniards.