Francis Drake's coffin is the coffin that Sir Francis Drake was apparently buried at sea inside.
The coffin was found by Nathan Drake and Elena Fisher off the coast of Panama, and was the first clue to track down El Dorado. Using the coordinates imprinted on Francis Drake's ring, pointing towards the location of the coffin, Nate discovered that Drake had faked his death. The date on the ring was also 29 January 1596, a day after his supposed death.
The coffin was marked with the coat of arms of Drake: the shield cut in half by a wave, with a star above the wave and below it.