The ancient civilization known for its advanced mathematics, astronomy, and the calendar is the Mayans. Flourishing in Mesoamerica, especially in parts of present-day Mexico, Guatemala, and Belize, the Mayans developed a sophisticated understanding of the cosmos, creating precise calendars that aligned with celestial events. Their achievements in mathematics, such as the concept of zero, significantly influenced their agricultural and ceremonial practices, marking them as one of the most advanced cultures of their time.