My parents would also send me all alone on a plane across the country to visit my grandparents during the summer starting when I was about 7. The airlines still let you do this, but not with kids that young anymore. I had to wear a huge plastic tag around my neck saying I was alone so that the flight attendants could keep an eye on me.
Yup, I did this as a kid too! My first trip solo was at 8. I "took care of" my little sis, who was 5. Honestly though, I feel like this was pretty safe. My parents saw us to the gate, and the flight attendent walked us onto the plane, and she then walked us off the plane and stayed with us until my Gramma took us over.
When I was staying at my grandparents' house during the summers, I ran completely free. Those are the most amazing and wonderful memories for me now, but I would TOTALLY never let my kids do it! My grandparents' house was backed up to acres upon acres of forest and I would just stay there all day every day and I only came back to the house for meals.
Once we survived our flight, then it was time to run free at my great aunt's farm (where my Gramma also stayed). The worst thing that ever happend was my sister falling through a rotten barn floor where my friends and I told her not to walk. Oh, and that same friend's farm was also where we got to shoot at a chicken with a .22 that got loose and kept escaping. The idea was that it would be supper and the kids each got to take a shot. Honestly, (other than the experience with the .22, which I was a bit young for at 8 or9) I would let my kid run free like this in a rural area well known to me. It was amazing and some of my best memories are there.
My grandmother also worked the art show at the county fair during summers and she would take me along with her every day. I had free run of the grounds. Me. A Seven year-old child all alone at a county freaking fair! Unbelievable! Still, I loved those days. I would spend hours walking around looking for tokens and tickets people had dropped and then use them to ride the rides and play the games. *sigh* Those were happy days.
This made me remember working the beer garden with my Gramma and her sister at 8 years old on! There was a big "fair" and my gramma, her sister and my great uncles would volunteer to run the bar (I think it was run by the lions or kinsmen) I hung out with all the grannies in the back going over and getting my uncles to "sneak" me pop while watching the crazy antics of all the drunk adults out on the dance floor. lol. My uncle snuck me into the same party when I was 16.