PYRAMID OF THE SUN, TEOTIHUACAN – MEXICO
The Pyramid of the Sun is the largest structure in Teotihuacan, and the second largest in Mesoamerica. It is also the third largest pyramid in the world.
The name Pyramid of the Sun comes from the Aztecs, who visited the city of Teotihuacan centuries after it was abandoned; It was constructed in two phases. The first construction stage, around 100 C.E., brought the pyramid to nearly the size it is today. The second round of construction resulted in its completed size of 224.942 meters (738 feet) across and 75 meters (246 feet) high, making it the third largest pyramid in the world, though still just over half the height of the Great Pyramid of Giza (146 metres).
The second phase also saw the construction of an altar atop of the pyramid, which has not survived into modern times. The Adosada platform was added to the pyramid in the early third century, at around the same time that the Ciudadela and Temple of the Feathered Serpent, Teotihuacan Pyramid of the Feathered Serpent were constructed.
But that’s not everything inside this pyramid. There’s a cave in there, a natural cave that was so important to the Teotihuacanos that they built a pyramid over it. The cave, which was enlarged and modified to serve ritual purposes long before the construction of the pyramid, now runs, 20 feet below the pyramid, for 330 feet from the stairway on the west, eastward toward the center. At its end is a room shaped rather like a four-leaf clover.
Width 230 meters (760 feet)
Height:65.5 meters (216 feet)
Base perimeter:794.79 square metres or 8,555.0 square feet
Side: 223.48 metres or 733.2 feet
1/2 side: 111.74 metres or 366.6 feet
(Source : http://www.philipcoppens.com/nap–art3.html)