Now the city of Acoma is one of those which are built upon a height. The builders chose the flat top of a barren sandstone cliff, containing about ten acres, which rises about three hundred feet above the plain. In New Mexico such table-lands are called _mesas_, from _mesa_, the Spanish word meaning table. Therefore, while no one knows its age, or history, all agree that Acoma must go far back into the past. Acoma was so strongly built that to-day it looks hardly different from what it did when the Spaniards first saw it, perched on the top of its rock, in 1582. We see then in the builders of Acoma a people gifted with a much higher order of intelligence than the Red Indian, who is always found living in huts, or hovels, of the rudest possible kind. The wild Indian always carries his house about with him, and so is ever ready, at a moment's notice, to "Fold his tent, like the Arabs, And as silently steal away." The sedentary Indian sometimes patterned his after the burrowing animals, like the beaver, and sometimes after the birds of the air, like the sparrow. Now to describe Acoma itself. It consists of ranges of massive buildings rising in successive tiers from the ground. The second story is set a little back from the first, and the third a little back from the second, so leaving a space in front of each range of buildings for the inhabitants or sentinels to walk about in, in peaceful times, or send down missiles upon the heads of their enemies in time of war. By running up the outer wall of each story, for a few feet higher than this platform, the builders made what is called a parapet in military phrase, meant for the protection of the defenders. There were no doors or windows except in the topmost tier. Acoma, then, was a castle built upon a rock. It would seem that only birds of the air or creeping things could gain admittance to such a place. Indeed, there was no other way for the inhabitants themselves to enter their dwellings except by climbing up ladders set against the outer walls of the building for the purpose. In this manner one could climb to the first platform, then to the second, but could not get in till he came to the roof, through which he descended by a trap door into his own quarters. [Illustration: ACOMA.] The whole collection of buildings being divided by partition walls into several blocks, each containing sixty or seventy houses, is, practically, the apartment hotel of to-day. The material commonly used was adobe,[3] or bricks dried and hardened in the sun. Such a building could not be set on fire or its walls battered down with any missiles known to its time. We see then that the Pueblo Indians must have had enemies whom they feared,—enemies at once aggressive, warlike, and probably much more numerous than themselves. How well they were able to meet these conditions, their houses show us to this day. [Illustration: CASA GRANDE, GILA VALLEY.]