Tulum. Recent developments Around 2006, the National Institute of Anthropology and History (INAH), which manages the archaeological site of Chichen Itza, started closing monuments to the public. While visitors may walk around them, they may no longer climb them or enter the chambers. This followed a climber falling to her death. Researchers discovered an enormous cenote (also known as a sinkhole) beneath the 1,000-year-old temple of Kukulcán. The forming sinkhole beneath the temple is approximately and as many as deep. The water filling the cavern is thought to run from north to south. They also found a layer of limestone approximately thick at the top of the cenote, upon which the temple sits. Recent archaeological investigations have used electrical resistivity tomography (ERT) to examine the construction sequence of Kukulcán. To preserve the site from potential damage, electrodes were placed non-traditionally as flat-based detectors around the quadrangle of the temple bodies. After each body of the temple was tested, the data revealed two previous construction phases within Kukulcán with a possible temple at the top of the second substructure. Determining the dates when these constructions happened will provide time periods of when Chichen Itza may have been significantly occupied. Gallery See also List of Mesoamerican pyramids Pyramid of the Magician at Uxmal Tikal Temple I Tikal Temple II Tikal Temple III Tikal Temple IV Tikal Temple V Notes References Šprajc, Ivan, and Pedro Francisco Sánchez Nava (2013). Astronomía en la arquitectura de Chichén Itzá: una reevaluación. Estudios de Cultura Maya XLI: p. 31–60. Gray, Richard. "Sacred Sinkhole Discovered 1,000-year-old-Mayan-Temple-Eventually-Destroy-Pyramid." Science & tech August 17, 2015. Dailymail. Web. August 17, 2015. Justice, Adam. "Scientists discover sacred sinkhole cave under Chichen Itza pyramid." Science (2015). Ibtimes. Web. August 14, 2015. Juárez-Rodríguez, O., Argote-Espino D., Santos-Ramírez, M., & López-García, P. (2017). Portable XRF analysis for the identification of raw materials of the Red Jaguar sculpture in Chichén Itzá, Mexico. Quaternary International, Quaternary International. Tejero-Andrade, A., Argote-Espino, D., Cifuentes-Nava, G., Hernández-Quintero, E., Chávez, R.E., & García-Serrano, A. (2018). ‘Illuminating’ the interior of Kukulkan's Pyramid, Chichén Itzá, Mexico, by means of a non-conventional ERT geophysical survey. Journal of Archaeological Science, 90, 1-11. Wren, L., Kristan-Graham, C., Nygard, T., & Spencer, K. R. (2018). Landscapes of the Itza : Archaeology and art history at Chichen Itza and neighboring sites. Gainesville: University Press of Florida. Buildings and structures completed in the 12th century Archaeoastronomy Chichen Itza Maya architecture