When divers discovered the wreck of an ancient vessel in the 1900s, little attention was given to a muddy box that was found alongside the wreckage.
It was only much later that it was discovered to contain bronze gears, forming part of a machine with such complexity that it almost re-wrote much of what was understood about the technological progression in Ancient Greece.
The Antikythera device is just one of a number that have been discovered, invented and then either destroyed or lost through the passage of time.
From the virtually indestructible Roman concrete that has lasted over a thousand years to Nikola Tesla's 'Earthquake Machine' which supposedly had the ability to topple any building simply by sending tiny vibrations through the structure.
These are the inventions that have ultimately changed the world and yet left no trace of their origins.