the addition of sloping walls to give it a pyramidal form. It is flat topped, and on the centre of its southern face there appears to have been steps to ascend to its summit. The second is a square altar, its height and base being each about sixteen feet. These buildings are surrounded at no great distance by a strong wall, and at a quarter of a mile to the northward, advantage is taken of a precipice to construct another wall of twelve feet in width from its brink. On a small flat space between this and the pyramid are the remains of an open square edifice, to the southward of which are two long mounds of stone, each extending about thirty feet; and to the northeast is another ruin, having large steps up its side. I should conceive the highest wall of the citadel to be three hundred feet above the plain, and the base rock surmounts it by about thirty feet more.
"The whole place in fact, from its isolated situation, the disposition of its defensive walls, and the favorable figure of the rock must have been impregnable to Indians; and even European troops would have found great difficulty in ascending those works which we have ventured to name the Citadel. There is no doubt that the greater mass of the nation who once dwelt here must have been established on the plain beneath, since from the summit of the rock we could distinctly trace three straight and very extensive causeways diverging from that over which we first passed. The most remarkable of these roads runs south-west for two miles, is forty-six feet in width, and crossing the grand causeway is continued to the foot of the cliff immediately beneath the cave which I have described. Its more distant extreme is terminated by a high and long artificial mound immediately beyond the river toward the hacienda of La Quemada. We could trace the second road south and south-west to a small rancho named Cayotl, about four miles distant, and the third ran south-west by south still farther, ceasing, as the country people informed us, at a mountain six miles distant. All these roads have been slightly raised, were paved with rough stones, still visible in many places above the grass, and were perfectly straight.
"From the flatness of the fine plain over which they extended, I cannot conceive them to have been constructed as paths, since the people who walked barefoot and used no beasts of burden, must naturally have preferred the smooth earthen foot-ways which presented themselves on every side, to these roughly paved roads. If this be admitted, it is not difficult to suppose that they were the centres of streets whose huts constructed of the same kind of frail materials as those of the present day, must long since have disappeared. Many places on the plain are thickly strewn with stones
