The galleon was discovered as workers dug the foundations of a block of flats
Construction workers in Argentina have struck oil - of the olive variety - as they unearthed a colonial-era Spanish ship believed to be 250 years old.
The galleon was discovered as workers dug the foundations of a block of flats in the old port area of Buenos Aires.
Two large jars found inside the ship seem to indicate that it had transported olive oil.
Experts believe the as-yet unidentified vessel was an 18th Century warship driven ashore by a storm.
It was subsequently buried under 7m (21ft) of mud.
Archaeologist Gonzalo Valenzuela said the vessel was probably from the 1700s.
"So far, it has yielded several cannons, a pair of jugs we think were used to carry olive oil, and timber from the ship," Mr Valenzuela told reporters at the digs in Puerto Madero, the AFP news agency reported.
While precious, the ship's contents are not thought to include gold
But he said there was unlikely to be any gold or other treasure on board as locals would have probably plundered the vessel after it ran aground near the shoreline.
Mayor Mauricio Macri of Buenos Aires said the only reason the ship had been found was through the cooperation of the construction workers with archaeologists, whose wishes to explore a building site might have been ignored in the past.
"What's important is that this wouldn't have happened if it wasn't for this new historic conscience, in this case the collaboration of the building company," said Mr Macri.
"In other construction sites in the past the archaeologists wouldn't even be allowed anywhere near the place. This company worked together with the archaeologists and we won this unexpected treasure."
He said the galleon and everything it contains belonged to the citizens of the Argentine capital.