The Antikythera mechanism (/ˌæntᵻkᵻˈθiːrə/ ANT-i-ki-THEER-ə or /ˌæntᵻˈkɪθərə/ ANT-i-KITH-ə-rə) is an ancient analogue computer and orrery used to predict astronomical positions and eclipses for calendrical and astrological purposes, as well as the Olympiads, the cycles of the ancient Olympic Games.