be traced by the remains of solid walls, to have been a square of thirty-one feet by the same height: the heap immediately opposite is lower and more scattered, but in all probability formerly resembled it. Hence the grand causeway runs to the northeast until it reaches the ascent of the cliff, which, as I have already observed, is about four hundred yards distant. Here again are found two masses of ruins, in which may be traced the same construction as that before described; and it is not improbable that these two towers guarded the inner entrance to the citadel. In the centre of the causeway, which is raised about a foot and has its rough pavement uninjured, is a large heap of stones, as if the remains of some altar; round which we could trace, notwithstanding the accumulation of earth and vegetation, a paved border of flat slabs arranged in the figure of a six-rayed star.
"We did not enter the city by the principal road, but led our horses with some difficulty up the steep mass formed by the ruins of a defensive wall, inclosing a quadrangle two hundred and forty feet by two hundred, which, to the east, is still sheltered by a strong wall of unhewn stones, eight feet in thickness and eighteen in height. A raised terrace of twenty feet in width passes round the northern and eastern sides of this space, and on its southeast corner is yet standing a round pillar of rough stones, of the same height as the wall, and nineteen feet in circumference.
"There appear to have been five other pillars on the east, and four on the northern terrace; and as the view of the plain which lies to the south and west is hence very extensive, I am inclined to believe that the square has always beep open in these directions. Adjoining to this, we entered by the eastern side to another quadrangle, entirely surrounded by perfect walls of the same height and thickness as the former one, and measuring one hundred and fifty-four feet by one hundred and thirty-seven. In this were yet standing fourteen very well-constructed pillars, of equal dimensions with that in the adjoining inclosure, and arranged, four in length and three in breadth of the quadrangle, from which on every side they separated a space of twenty-three feet in width: probably the pavement of a portico of which they once supported the roof. In their construction, as well as that of all the walls which we saw, a common clay having straw mixed with it has been used, and is yet visible in those places which are sheltered from the rains. Rich grass was growing in the spacious court where Aztec monarchs may once have feasted; and our cattle were so delighted with it that we left them to graze while we walked about three hundred yards to the northward, over a very wide parapet, and reached a perfect, square, flat-topped pyramid of large unhewn stones. It was standing unattached to any other buildings, at the foot of the eastern brow of the mountain, which rises abruptly behind it. On the eastern face is a platform of twenty-eight feet in width, faced by a parapet wall of fifteen feet, and from the base of this extends a second platform with a parapet like the former, and one hundred and eighteen feet wide. These form the outer defensive boundary of the mountain,
