According to reports, the enormous 650 square-mile regions, known as the Mirador-Calakmul Karst Basin, is located close to the Mexican border. Archaeologists estimate that the city must have existed 2,000 years ago and that it must have consisted of about 1,000 settlements connected by 110 miles of causeways. If we believe what they found, we must assume that the city existed 2,000 years ago. The team also discovered pyramids and platform remnants.