When I was 12 years old, my friends and I used to bike about 8 miles to the airport to see airplanes take off from a nearby hill. The hill was federal land, delimited by simple wire fencing, so we would climb it to get to the hill. The path was clearly there, so we must not have been the only ones there. As long as we came back before the light came on, we would be fine with my parents. Once, we had to cross a freeway and a truck hit our dog, who died. There was nothing we could do for it, so we left it there. We never went back after that.
If a kid was caught doing that today, it would legally be taken away form his/her family by Children Protective Services, the parents charged, tried, and probably convicted of child neglect and endangerment.
Some of the best memories from childhood for me are those trips. How sad that kids have to be home playing with their iPads today.