With the dawn we were up and out at El Castillo, to use the stupid Spanish name of the great pyramid. It loses none of its majesty in the daylight. It is a truncated pyramid close on 100 feet high, squared almost to the four cardinal points, but not, we believe, orientated; the northern side being the front because in that direction lies the Sacred Cenote which we shall describe in a moment. The four base lines are each, as near as can be, 200 feet long. On each of the four sides were gigantic staircases. That on the west, still in fair preservation, up which we must climb directly, is 37 feet wide. That on the north was 44, but this latter and that on the east are so entirely destroyed as to be barely traceable. The stairs on the south, about 40 feet wide, are much broken and overgrown by cactus and shrub. The pyramid is built of rubble and earth, and was completely faced with flat-hewn slabs of limestone about 5 feet by 4 and 4 to 6 inches thick. In places these are still in position. This is particularly the case with the south front. The four corners were evidently once dressed with rounded stone blocks from top to bottom. It is difficult to exaggerate the magnificent appearance the mound must have once presented. The stairways, which are so steep as to appear in some places almost perpendicular, were balustraded, each balustrade ending on the ground in those gigantic carved stone serpent-heads, the jaws wide gaping, which we find again and again in Mayan ruins. The climb of the 120 steps, on the average about 9 inches high and 8 broad, is an undertaking before which any one not a practised Alpine climber might be excused for quailing. Pausing for breath at the eightieth step and looking downwards, your head reels; for the edges of the steps appear to merge into one another by reason of their steepness, giving one the feeling of being perched, fly-like, on the face of a grey cliff. On reaching the top step, a few feet of platform separates you from the temple. Climbing as you have been from the western side, the real one-time grandeur of the sanctuary does not strike you. It is not the front, and you must pass to the north, where was the state entrance to the Holy of Holies. This is 20 feet wide and the lintel of the gigantic doorway is supported by two pillars, 8-1/2 feet high, carved with a snake pattern and once ending at the base in snakes' heads, open-mouthed, the now empty eye-sockets having once been filled with brilliantly painted stone or pieces of polished jade. These heads are broken up, and only enough remained for the tutored eye to reconstruct the whole. Entering, you are in a now roofless room running the full length of the building east to west, 40 feet long and 6 broad. In front of you is a second doorway, its massive door-posts carved with life-sized figures of warriors in full ceremonial dress. By this you enter the central room, 20 feet by 12. Two pillars, each 1 foot 10 inches square,