The treasure comes from the Spanish galleon San Jose which sank more than 300 years ago after fleeing from British warships, according to the Associated Press. The ship may have been carrying over 11 million gold coins and jewels from Spanish colonies, which could be worth billions.

Although specifics of the location are being kept secret, the ship apparently sank near Colombia’s Baru peninsula, south of Cartagena. A recovery effort is expected to take years, said Colombia’s President, Juan Manual Santos.

In a press conference, he announced that no humans have reached the shipwreck yet. The galleon’s location was determined by experts using autonomous underwater vehicles.

But the search for the ship has been enmeshed in a legal battle for decades, the AP reported. A group called Sea Search, owned by U.S. investors, said they had found the location of the ship in 1982. The announcement led to Colombia’s government overturning maritime law in 1984 so that those who find a shipwreck get a cut of just 5% as opposed to 50%.

The U.S. investors had a lawsuit related to finding the ship dismissed in Washington in 2011, with a ruling affirmed on appeal in 2013.

Colombia’s Supreme Court ordered the ship to be recovered before the dispute is settled, according to the AP.