On looking at the map of the State of Mexico, there is to be seen a river which stops suddenly on reaching the mountains of Cacahuamilpán, and begins again on the other side, having found a passage for itself through caves in the mountain for six or seven miles. Not far from the place where this river flows out of the side of the hill, is a path which leads to the entrance of the cave. A long downward slope brought us into the first great vaulted chamber, perhaps a quarter of a mile long and eighty feet high; then a long scramble through a narrow passage, and another hall still grander than the first. At the end of this hall is another passage leading on into another chamber. Beyond this we did not go. As it was, we must have walked between one and two miles into the cavern, but people have explored it to twice this distance, always finding a repetition of the same arrangement, great vaulted chambers alternating with long passages almost choked by fallen rocks. In one of the passages, I think the last we came to, the roaring of the river in its subterranean bed was distinctly audible below us. Excepting the great cave of Kentucky, I believe there is no stalactitic cavern known so vast and beautiful as this. The appearance of the largest hall was wonderful when some twenty of our Indian guides stationed themselves on pinnacles of stalagmite, each one holding up a blazing torch, while two more climbed upon a great mass at one end called the altar, and burnt Bengal lights there; the rest stood at the other extremity of the cave sending up rockets in rapid succession into the vaulted roof, and making the millions of grotesque incrustations glitter as if they had been masses of diamonds: All the quaint shapes that are found in such caverns were to be seen here on the grandest scale, columns, arched roof, organ-pipes, trees, altars, and squatting monsters ranged in long lines like idols in a temple. There may very well be some truth in the notion that the origin of Gothic architecture was in stalactites of a limestone cavern, so numerous and perfect are the long slender columns crowned with pointed Gothic arches. Our procession through the cave was a picturesque one. We carried long wax altar-candles and our guides huge torches made of threads of aloe-fibre soaked in resin and wrapped round with cloth, in appearance and texture exactly like the legs and arms of mummies. As we went, the Indians sang Mexican songs to strange, monotonous, plaintive tunes, or raced about into dark corners shouting with laughter. They talked about adventures in the cave, to them of course the great phenomenon of the whole world; but it did not seem, as far as we could hear, that they associated with it any recollections of the old Aztec divinities and the mystic rites performed in their honour.