Keep in mind that Yugoslavia was a completely different thing during the cold war. It was a communist country that was not part of the Comintern, or the Warsaw pact. It, in fact, had open borders with the west.
This caused it to be in a much better place economically than the rest of the communist world.
There's an old nostalgic american tourist piece about it: https://www.youtube.com/watch?v=0RRnCnO1Y2c&has_verified=1