Wait a minute now...
Wasn’t Scandinavian under it’s own separate glacier during the last glacial? I’m pretty sure it was, and the deepest part was where the Baltic sea is now, similar to Hudson’s Bay in Canada—vast footprints of the center of a massive ice sheet.
After the ice melted, the land, which had been sunk under the ice sheet, has slowly sprung back—in fact, in some places, it still is rising.
Perhaps that lowland was a bay or harbor on the water then.
maybe..a bay or cove that orca used to herd bluefin, which the indigenous capitalized on? It’d be interesting to compare the orca bones with specimens of those in the below article, which speaks of existing 5,000 year old pods who hunt and herd bluefin in waters less than 300 meters depth and can be seen 100 meters from the beach.