English: The Castle, El Castillo, is actually quite unique in the Mayan World. It stands 17 meters high, making it taller than any of the buildings in Tulum or elsewhere on the coast. This pyramid is a great example of the Mesoamerican tradition of adding newer and bigger structures on top of old temples. There are at least four different layers of construction of El Castillo. The remodeling of temples was done for various reasons, for example to celebrate a new ruler or the coming of a new era. A round tower presides on the top of the pyramid, which is an unusual feature in Mayan architecture. At the top of its stairway is an alter, where investigators have discovered two offerings containing a total of 264 ornamental objects fashioned from green stone or jadeite and shell. Beads, lip rings, ear flares, plaques, pendants, rings, a knife made of flint and a clay incensory were found among the offerings. On the east side is an entrance, over which a frieze of two stucco herons served as architectural ornamentation. (I could not see these as there was no way to reach them).