While digging for an ancient settlement in southern Sweden, archaeologists made a completely unexpected discovery: a huge Viking Age cemetery with more than 100 graves and several ship-shaped burial mounds.

From the start of the excavations, “we realized that there was a large Viking cemetery that we had to focus on,” explains the project leader. Petra Nordinarchaeologist at the National Historical Museums of Sweden, said in a statement. “We’ve only searched six percent of the cemetery.”