An underwater robot discovered the shipwreck of a Spanish ship more than 300 years old containing gold and treasure worth up to $17 billon, according to a report.

Though the shipwreck was discovered three years ago, the underwater robot’s part in the discovery has only just been revealed.

According to WBUR News, “A Spanish galleon laden with gold that sank to the bottom of the Caribbean off the coast of Colombia more than 300 years ago was found three years ago with the help of an underwater autonomous vehicle operated by the Woods Hole Oceanographic Institution.”

“The exact location of the wreck of the San Jose, often called the ‘holy grail of shipwrecks,’ was long considered one of history’s enduring maritime mysteries,” they explained, adding that the treasure found on board “is worth as much as $17 billion by modern standards.”

The underwater robot, REMUS 6000, was donated to the search by the Woods Hole Oceanographic Institution (WHOI) and has previously found other wrecks, including an Air France plane which crashed in 2009.

“The REMUS 6000 was the ideal tool for the job, since it’s capable of conducting long-duration missions over wide areas,” declared WHOI engineer Mike Purcell. “The wreck was partially sediment-covered, but with the camera images from the lower altitude missions, we were able to see new details in the wreckage and the resolution was good enough to make out the decorative carving on the cannons… MAC’s lead marine archaeologist, Roger Dooley, interpreted the images and confirmed that the San José had finally been found.”