The Antikythera mechanism consists of a complex assembly of bronze gears housed in a wooden box. When operated by a hand-crank, these gears could simulate the motions of the sun, moon, and planets, providing an accurate representation of the celestial cycles. It includes a dial that tracks the Metonic cycle, a 19-year period crucial for calculating the calendar, and another for predicting solar and lunar eclipses based on the Saros cycle.