Calakmul is a pre-Hispanic Mayan archaeological site, located in the southeast of the Mexican state of Campeche, in the Petén region, in the core of the Calakmul biosphere reserve, of more than 700,000 ha, municipality of the same name and a few kilometers of the border with Guatemala. The site covers approximately 70 km² and has more than 6000 structures and became the capital of a regional state of approximately 13,000 km², having been, together with Tikal and Palenque, one of the great regional powers, during the classic period of the Mayan culture. Initially registered in 1931 by the biologist Cyrus Longworth Lundell, it was initially explored by the famous Mayan Sylvanus Morley in 1932.
However, it was not until half a century later, beginning in 1982, when large-scale excavations were carried out. William Folan, Center for Historical and Social Research of the Autonomous University of Campeche and the National Institute of Anthropology and History of Mexico. The study initiated by the team of Folan, concluded that they were before a center of the Mayan civilization, of great proportions, determining that, according to the period, it came to count on more allies and power than the own Tikal. In addition, from the 90s, it is concluded that Calakmul belonged to a much larger organization. It was part of the so-called Kingdom of the Serpent, the kingdom of Kaan or Kan, of which concretely, it constituted the capital.
The great advance in the study of the Mayan writing, that is obtained during these years, gives rise to that the investigators have discovered that Calakmul and Tikal carried out festering wars, during more than a century. Clashes that would mark the political, economic and social development of the Mayan cities of the region. Calakmul is now the object of a large-scale project of the National Institute of Anthropology and History, which began in 1993. Due to the importance of the site, on July 4,2002, Unesco granted it the designation of Cultural Heritage of Humanity, extending the distinction to Mixed Humanity Heritage, on June 21,2014, recognizing the natural values within the Biosphere Reserve.