Earlier this summer, an 8-year-old girl named Saga Vanecek was doing what she often does: wading in Sweden's Lake Vidostern.
"I like to walk around finding rocks and sticks in the water, and then I usually walk around with my hands and knees in the water and in the sand," she explained to Radio Sweden Wednesday.
It was then that she felt something odd beneath her hand and knee. She lifted the object and saw that it had a handle.
She pulled it out of the water and carried it over to her father. "Dad, I found a sword," she said.
"I'm not sure you should be touching it anymore," he replied. "It looks fragile."
Saga and her father took the sword to authorities and found that it was very old indeed.
"Indeed an amazing story!" Mikael Nordstrom, head of the cultural heritage department at the Jonkopings County Museum, told NPR in email. "We now believe that the sword is about 1,500 years old."
According to the museum, the sword is about 33 inches long and "exceptionally well-preserved." It even has a sheath made of wood and leather.
Further searching in the lake yielded a piece of metal jewelry from A.D. 300-400.
In the coming days, a team including the Jonkopings County Museum, the county's administrative board and members of the Swedish Metal Searchers Association will conduct additional searches of the area. They hope to find other items that could offer clues about the sword and the jewelry.
Conservators are examining the items, and it will be at least a year before the sword will be exhibited, Nordstrom told Swedish news site The Local.
"Why it has come to be there, we don't know," he told the site. "But perhaps it's a place of sacrifice. At first we thought it could be graves situated nearby the lake, but we don't think that anymore."
Saga moved with her family to Sweden just last year, The Local reports. She grew up in Minneapolis, and her father is from Minnesota.
And what does Saga think of her ancient discovery?
"That it was pretty cool and that it was exciting," she told Radio Sweden. "It's not that common that you find a sword that is 1,500 years old!"
NPR's Liana Simstrom contributed to this report.