Three Viking boats embedded in the shores of an Icelandic fjord have been discovered in three days, Iceland Magazine reports. The artifacts, which include a vessel that once belonged to an affluent chief, join the small number of boat burials that have been recorded in the Nordic country.

Archaeologists came upon the first boat last week on the shore of the Dysnes peninsula bordering the Eyjafjörður fjord in northern Iceland. It contains the bones of a person and the teeth of a dog that was buried with him, both believed to date back to the 9th or 10th century. A sword found among the remains indicates the grave belonged to someone of Viking nobility.

The next day, the researchers discovered another boat burial, and it was in even better condition than the first. The day after that, they found two graves and some wooden nails that are likely from yet another boat. The finds are all thought to be about 1000 years old.

Boat funerals, in which the deceased were loaded into ships with their possessions before being launched out to sea, have become synonymous with Viking culture. But the ritual wasn’t as common as pop culture makes it seem today: Only 10 or so boat burials have ever been discovered in Iceland. And when they have been found, they’ve rarely been clustered together like this most recent trio of finds.

The finds are under threat—not from grave robbers but from the tide of the nearby fjord. Half of the first vessel and its contents have already been swept into the sea over the past millennium, and the the other two ships have sustained damage from erosion. Archaeologists plan to continue excavating the boats in the weeks ahead.

[h/t Iceland Magazine]