Archaeologists have found the outlines of a Viking ship buried not far from the Norwegian capital of Oslo. The 65-foot-long ship was covered over more than 1,000 years ago to serve as the final resting place of a prominent Viking king or queen. That makes it one of the largest Viking ship graves ever found.

Experts say intact Viking ship graves of this size are vanishingly rare. “I think we could talk about a hundred-year find,” says archaeologist Jan Bill, curator of Viking ships at the Museum of Cultural History in Oslo. “It’s quite spectacular from an archaeology point of view.”

The site where the ship grave was found is well-known. A burial mound 30 feet tall looms over the site,