The Antikythera mechanism

[Davey Boy 2.0]

pretty mind blowing:

Quote

The Antikythera mechanism (/ˌæntᵻkᵻˈθɪərə/ ANT-i-ki-THEER-ə or /ˌæntᵻˈkɪθərə/ ANT-i-KITH-ə-rə) is an ancient analog computer^[1][2][3][4] designed to predict astronomical positions and eclipses for calendrical and astrological purposes,^[5][6][7] as well as the Olympiads, the cycles of the ancient Olympic Games.^[8]

Found housed in a 340 mm × 180 mm × 90 mm wooden box, the device is a complex clockwork mechanism composed of at least 30 meshing bronze gears. Its remains were found as 82 separate fragments, of which only seven contain any gears or significant inscriptions.^[9][10] The largest gear (clearly visible in Fragment A at right) is approximately 140 mm in diameter and originally had 223 teeth.

The artifact was recovered in 1900–1901 from the Antikythera shipwreck off the Greek island of Antikythera.^[11] Believed to have been designed and constructed by Greek scientists, the instrument has been dated either between 150 and 100 BC,^[5] or, according to a more recent view, at 205 BC.

https://en.wikipedia.org/wiki/Antikythera_mechanism