It stood in the midst of a vast area, encompassed by a wall of stone and lime, about eight feet high, ornamented on the outer side by figures of serpents, raised in relief, which gave it the name of the _coatepantli_, or “wall of serpents.” This emblem was a common one in the sacred sculpture of Anahuac, as well as of Egypt. The wall, which was quadrangular, was pierced by huge battlemented gateways, opening on the four principal streets of the capital. Over each of the gates was a kind of arsenal, filled with arms and warlike gear; and, if we may credit the report of the Conquerors, there were barracks adjoining, garrisoned by ten thousand soldiers, who served as a sort of military police for the capital, supplying the emperor with a strong arm in case of tumult or sedition.[372] The _teocalli_ itself was a solid pyramidal structure of earth and pebbles, coated on the outside with hewn stones, probably of the light, porous kind employed in the buildings of the city.[373] It was probably square, with its sides facing the cardinal points.[374] It was divided into five bodies or stories, each one receding so as to be of smaller dimensions than that immediately below it,--the usual form of the Aztec _teocallis_, as already described, and bearing obvious resemblance to some of the primitive pyramidal structures in the Old World.[375] The ascent was by a flight of steps on the outside, which reached to the narrow terrace or platform at the base of the second story, passing quite round the building, when a second stairway conducted to a similar landing at the base of the third. The breadth of this walk was just so much space as was left by the retreating story next above it. From this construction the visitor was obliged to pass round the whole edifice four times in order to reach the top. This had a most imposing effect in the religious ceremonials, when the pompous procession of priests with their wild minstrelsy came sweeping round the huge sides of the pyramid, as they rose higher and higher, in the presence of gazing multitudes, towards the summit. The dimensions of the temple cannot be given with any certainty. The Conquerors judged by the eye, rarely troubling themselves with anything like an accurate measurement. It was, probably, not much less than three hundred feet square at the base:[376] and, as the Spaniards counted a hundred and fourteen steps, was, probably, less than one hundred feet in height.[377]