Poseidon's Trident

The Trident was a trinity of massive cannons found on Poseidon's massive warship. A single shot from one of the cannons could level entire mountains and cause massive tsunamis when fired directly at the ocean. When all 3 cannons are converged, it had enough firepower to decimate a continent with a single shot, though this was never attempted.

It was a symbol of Poseidon's power. During the war that brought down Atlantis to its knees, Poseidon, knowing that his end was coming, overloaded the core of his ship and crashed it onto the ocean, generating a massive tsunami that was responsible for the Great Deluge. The catastrophic event was so devastating that it threw civilization back to the stone age. The cannons eventually became lost as the ship sunk, assumed to have been destroyed and eventually forgotten, until it was accidentally discovered by the NOAA in 2005 somewhere deep in the Atlantic Ocean.