I grew up in a rural area, and we were always allowed to play unsupervised within about a 500m radius of our house -- we just weren't allowed to cross the highway (and our street was bound on the other two sides by two rivers -- we weren't allowed to go swimming unsupervised until we were in our teens). We visited Sydney frequently, however, and I was allowed out on my own in the city from the age of 13 or so, although "allowed" is probably not quite the right word for it. It was more a case of my dad saying, "I think you can go out on your own now, so do it." I was also allowed to take my younger brother and sister out into the city at around this age. When I moved to Sydney for uni, I was definitely a lot more comfortable with being in the city than many of my peers, from both rural and urban areas.