The Castle or Pyramid of Kukulcan. One of the tallest and most remarkable examples of Maya architecture, it was built during the high point of the Itza-Cocom culture, during the decadence of Mayapan. It is a four-sided pyramid, with a rectangular temple on the top. The light and shadow phenomenon. Testimony of the amazing advance of the Maya in architecture and astronomy is the “light and shadow” phenomenon that takes place on the northern staircase of the Castle during the Spring Equinox on the 21st of March and the Autumn Equinox on the 21st of September. About three o’clock in the afternoon on the days of the equinox the sun projects seven triangles of light onto the balustrade on the northeastern side of the Castle. These begin to move up and down along the balustrade to form the silhouette of a serpent. The building sits on a rectangular platform, 55.5 meters (182 feet) wide and has a height of 24 meters (78 feet). Precision and intention are part of the essence of the building, each side of the pyramid has a large staircase, 91 steps per side and one more leading to the upper temple, giving 365 steps, one per day of the year. Stone balustrades flank each staircase, and at the base of the north staircase sit two colossal, feathered serpent heads, effigies of the god Kukulcan. It is in these stairways, and very particularly in their parapets or balustrades, where the shadows of the edges of the platforms or superimposed bases that integrate the great building are projected around the equinoctial day, thus configuring the image of the body of the serpent, that as the hours pass seems to move descending and ending in the mentioned stony head located in the inferior base of the stairway. The Castle or Pyramid of Kukulcan 是瑪雅建築最高、最引人注目的例子之一，建於伊察科科姆文化的鼎盛時期，也是瑪雅潘的衰落時期。它是一個四面金字塔，頂部有一個長方形的寺廟。 光影現象。 3月21日春分和9月21日秋分期間城堡北樓梯上發生的「光影」現象證明了瑪雅人在建築和天文學方面的驚人進步。春分日下午三點左右，太陽將七個三角形的光投射到城堡東北側的欄桿上。它們開始沿著欄桿上下移動，形成蛇的輪廓。 建築物坐落在一個長方形平台上，寬 55.5 公尺（182 英尺），高 24 公尺（78 英尺）。精準和意圖是這座建築精髓的一部分，金字塔的每一側都有一個大樓梯，每側有 91 個台階，還有一個通往上層寺廟的台階，共有 365 個台階，一年中每天一個。每個樓梯兩側都有石欄桿，北樓梯的底部有兩個巨大的羽蛇頭，這是庫庫爾坎神的肖像。正是在這些樓梯中，特別是在它們的護欄或欄桿中，平台邊緣的陰影或與這座偉大建築融為一體的疊加底座在春分日投射出來，從而形成了蛇身的形象，隨著時間的流逝，它似乎在下降，並在位於樓梯底部的上述石頭處結束。