reflected the common practice by the Maya of executing several phases of construction for their temples. The last construction probably took place between 900–1000 AD, while the substructure may have been constructed earlier, between 600–800 AD. Based on archaeological research, construction of Kukulcán was based on the concept of axis mundi. Anthropologists think that the site remained sacred regardless of how the structure was positioned on the location. When a temple structure was renewed, the former construction was destroyed using a ritual that involved resolving the space of spiritual forces to preserve its sacredness. It is estimated that this last construction dates to the eleventh century AD. The older, inner temple is referred to as the "substructure". After all of the restoration work was completed, an entryway was cut into the balustrade of the northeastern exterior staircase to provide access to tourists. Interior In 1566, the temple was described by Friar Diego de Landa in the manuscript known as Yucatán at the Time of the Spanish Encounter (Relación de las cosas de Yucatán). Almost three centuries later, John Lloyd Stephens described the architecture of the temple with even more detail in his book Incidents of Travel in Yucatán (Incidentes del viaje Yucatán), published in 1843. At that time, the archaeological site of Chichén Itzá was located on an estate, also called Chichén Itzá, owned by Juan Sosa. Frederick Catherwood illustrated the book with lithographs depicting the temple covered in abundant vegetation on all sides. There are some photographs taken in the beginning of the twentieth century that also show the temple partially covered by said vegetation. In 1924, the Carnegie Institution for Science in Washington, D.C. requested permission from the Mexican government to carry out explorations and restoration efforts in and around the area of Chichen Itza. In 1927, with the assistance of Mexican archaeologists, they started the task. In April 1931, looking to confirm the hypothesis that the structure of the temple of Kukulcán was built on top of a much older temple, the work of excavation and exploration began in spite of generalized beliefs contrary to that hypothesis. On June 7, 1932, a box with coral, obsidian, and turquoise encrusted objects was found alongside human remains, which are exhibited in the National Anthropology Museum in Mexico City. The Temple of Kukulcán (El Templo) is located above a cavity filled with water, labeled a sinkhole or cenote. Recent archaeological