the connection of the title to the actual site is ambiguous. Location Calakmul is located in Campeche state in southeastern Mexico, about north of the border with Guatemala and north of the ruins of El Mirador. The ruins of El Tintal are to the southwest of Calakmul and were linked to both El Mirador and Calakmul itself by causeway. Calakmul was about south of the contemporary city of Oxpemul and approximately southwest of La Muñeca. The city is located on a rise about above a large seasonal swamp lying to the west, known as the El Laberinto bajo (a Spanish word used in the region to denote a low-lying area of seasonal marshland). This swamp measures approximately and was an important source of water during the rainy season. The bajo was linked to a sophisticated water-control system including both natural and artificial features such as gullies and canals that encircled a area around the site core, an area considered as Inner Calakmul. The location of Calakmul at the edge of a bajo provided two additional advantages: the fertile soils along the edge of the swamp and access to abundant flint nodules. The city is situated on a promontory formed by a natural high limestone dome rising above the surrounding lowlands. This dome was artificially levelled by the Maya. During the Preclassic and Classic periods settlement was concentrated along the edge of the El Laberinto bajo, during the Classic period structures were also built on high ground and small islands in the swamp where flint was worked. At the beginning of the 21st century the area around Calakmul remained covered by dense forest. During the 1st millennium AD the area received moderate and regular rainfall, although there is less surface water available than further south in Guatemala. Calakumul is now located within the Calakmul Biosphere Reserve. The area conserved within the Reserve was conceptualized by the Centro de Investigaciones Historicas y Sociales de Universidad Autónomous de Campeche (CIHS/UAC). Population and extent At its height in the Late Classic period the city is estimated to have had a population of 50,000 inhabitants and to have covered an area of over . The city was the capital of a large regional state with an area of about . During the Terminal Classic the city's population declined dramatically and the rural population plummeted to 10% of its former level. The Late Classic population density