An eight-year-old going for a swim in a lake in southern Sweden made an exciting discovery, stumbling upon a pre-Viking sword.

Se de arkeologiska fynden i sjön Vidöstern. I somras hittades ett mycket gammalt svärd och sen dess har flera intressanta fynd gjorts. Foto @anders_kraft #arkeologi @raa_se_all pic.twitter.com/FpyHRYf2KD — Länsstyrelsen Jkpg (@jonkopings_lan) October 4, 2018

Mikael Nordström of the Jönköpings Läns Museum in Sweden said Friday that the girl, Saga Vanecek, found an 85 cm sword with preserved leather and wood around it, and experts who examined the object say it is from the fifth or sixth century, predating the Viking era.

Saga had been in the water in the Vidöstern lake in Tånnö, Småland, during the summer when she stepped on the object—which she thought was a stick at first.

“I picked it up and was going to drop it back in the water, but it had a handle, and I saw that it was a little bit pointy at the end and all rusty,” Saga told the Local.

The ancient sword discovery prompted teams of researchers, including those from the museum, to search the area for more prehistoric treasures. Researchers eventually found a broach estimated to be made between 300 A.D. and 400 A.D.

“We asked Saga [not to tell anyone about the sword] because we were afraid that if this find would go public too soon, there would be a lot of people there, perhaps destroying our possibility to find things later,” Nordström said.

Saga said the only person she told was her best friend, but she was allowed to reveal her story to her classmates Thursday.

“They thought that it was very fun and interesting to know about my story,” she said.

“I think maybe I found it harder to keep secret than she did,” Andy Vanecek, the girl’s father, said. “It’s cool that it will be in a museum and it might even say ‘Saga’s sword’ and it might be there for thousands of years.”