The remains of a man, a dog and a horse were found during a rare discovery of two Viking burial boats in Sweden, archaeologists announced last week.

Archaeologists discovered the boats, which could be more than 1,400 years old, in Gamla Uppsala, north of Stockholm, according to Arkeologerna and the National Historical Museums in Sweden.

Such boat graves were where important members of Viking society were laid to rest, probably between 550 to 800 AD and 800 to 1500 AD. Customarily, they were buried alongside jewelry and other riches or gifts.

In these graves, the archaeologists also found “a sword, spear, shield, and an ornate comb.”

The boats were the first in nearly 50 years to be excavated from the Uppsala area. Before this discovery, 10 boats had been uncovered in Sweden.

“It is extremely exciting for us since boat burials are so rarely excavated,” archaeologist Anton Seiler said in a news release.

The findings are unique because such graves remained “well preserved.” It was more common to cremate the dead in Viking society, according to the release.

The archaeologists noted that since this grave stayed immune to plundering, it offers great insight for research and study of the rare Viking burial practices.

“We can now use modern science and methods that will generate new results, hypotheses and answers,” Seiler said.