A Scandinavian mile is a measurement of distance that people used to use in countries like Denmark, Norway, and Sweden a long, long time ago. It's kind of like telling someone how far away something is, but using a special way of measuring.
Imagine you're playing outside with your friends, and your mom calls you in for dinner. She might say, "Come inside, it's time to eat. You need to walk four blocks to get to the house." That's a way of measuring distance that you're probably used to hearing.
But a long time ago in Scandinavia, people didn't use blocks to measure distance. Instead, they had a different way of measuring called a mile. A mile was the distance that someone could walk in a certain amount of time, usually about 15 minutes. So if someone said, "The store is two miles away," that meant it would take you about half an hour to walk there.
Nowadays, most people in Scandinavia use kilometers to measure distance, which is a different kind of measurement. But back in the olden days, a Scandinavian mile was a common way to describe distances.