Switzerland represent!
Yeah, I had a similar Upbringing. We went out and just did whatever outside. Then back for Lunch and then out again. Running around in the woods, building dams in the small stream, and so on. We were at the fringe of a small suburban town right next to some woods. I think we also ranged about 1-1.5 Miles away from home. We did have some boundaries set up by our parents, but that was really more to kind of limit the places they needed to check whether we fell asleep somewhere or something. The area was certainly big enough and exciting enough to tide us over.
And when I was 11, I was given a card for public transportation and we went to school in the "big" city (biggest city in CH). We took public transportation, switched modes 2 times (10 min walking to the train station, 15 min train ride, 12 min tram ride, 20 min bus ride). After the initial confusion over how public transport works, where all the info is located at the stations, no big deal. We usually rode in a group of 2-3, but if you missed a connection, you'd ride alone.
I feel that Switzerland has (had? I don't have kids... no real idea how it is 20 years later) a healthy attitude towards this stuff. Maybe that's just because I grew up there, but I feel that having an environment where we feel that children can roam around without getting murderized at every corner is something all societies should strive towards. And this absurd helicopter parenting I hear about sounds like it's trying to mitigate symptoms, not alleviate the root cause.