The entire structure measured 29 metres (about 95 feet) in height; 66 metres (214 feet 6 inches) in length at the base, and 33 metres (107 feet 3 inches) in width. The lower part is formed of the frustum of an elliptical cone 14 metres (45 feet 6 inches) in height, divided into 7 gradients, each 2 metres high. On the upper plane of the frustum, which forms a terrace 35 metres long by 10 metres wide, are constructed the Sanctuary, or Holy of Holies, facing west, whose ground plan is made in the shape of a cross with a double set of arms; and a truncated rectangular pyramid 6 metres high, the upper plane of which supports the crowning edifice 6 metres high, 29 metres long and 7 metres wide. [Illustration: GROUND PLAN OF SANCTUARY.] This building emblem of the "Lands of the West," is composed of three separate apartments 2m. 25c. wide, having originally no communication with each other. Holes have been bored in the partition walls that have much weakened the construction; for what purpose it is difficult to surmise, unless it be for the love of destruction. The rooms at the extremities are of the same size, 5m. 50c. (about 17 feet 10 inches) long, while the middle chamber is 7m. 25c. in length. The door of this chamber faced west, and led, by means of a small stair, to a terrace formed by the roof of the sanctuary. [Illustration: GROUND PLAN OF TEMPLE OF MYSTERIES.] From there the learned priests and astronomers, elevated above the mists of the plains below, could without hindrance follow the course of the celestial bodies, in the clear cloudless skies of Yucatan, where at times the atmosphere is so pure and transparent that stars are clearly visible to the naked eye, that require the aid of the telescope to be seen in other countries. The doors of the other rooms faced East. The ceilings, like those of all the apartments in the monuments of Yucatan and Central America, form a triangular arch. This shape was adopted by the builders, not because they were ignorant of how to construct circular arches—since they erected edifices roofed with domes, but in accordance with certain esoteric teachings pertaining to the mysteries and relating to the mystic numbers 3.5.7. This kind of arch is also found in the ancient tombs of Chaldea, at Mughier—in the center of the great pyramid of Ghizeh, in Egypt—in the most ancient monuments of Greece, as the treasure room at Mikéné, in the tombs of Etruria and other places.