The dodecahedron .
This is a mysterious object probably dating back to the 2nd-3rd century AD, found in multiple specimens from Great Britain to Hungary, passing through France, Germany and Italy.
However, no written source that has reached us seems to mention it, and this instrument does not appear in any image , and so scholars can only speculate on how it worked and what it was used for.
These are small, hollow bronze or stone objects , composed of 12 flat pentagonal faces, each with a circular hole in the center. These enigmatic objects range in size from 4 to 11 centimeters.
Hypotheses of all kinds have been formulated, imagining functions linked to astronomy and the agricultural cycle or to religious or esoteric rites.
There are also those who think that they were toys , or tools to help technicians and engineers, perhaps to measure distances.
Finally, some hypothesize that they had a military use and in particular that they helped in the production of slingshot bullets.
All hypotheses formulated with care but lacking any evidence to confirm them.