I'm 34 and remember all that stuff, too.
When I was growing up, we had a huge back yard. All the way in the back was a giant oak tree that was perfect for climbing and just off the back patio was another oak that was a little smaller. Every summer my father would string up a rope (1" thick at least) from the tree in the back to the tree in the front and hung a pulley w/ rope seat on it. Every kid in the neighborhood would be in our backyard flying down this zip line! Not only did you have to climb half way up this huge tree to get into the seat, if you didn't put your feet down and stop yourself you'd end up kissing the tree at the end of the line... but no one ever got hurt. When my father wasn't at home, no one used the zip line, period.
We moved when I was 9 and the new neighborhood didn't have any trees suitable for this.

But a few years after we were there the city started installing sewers in our neighborhood. That was the best summer for playing "Army" as I've ever had... trench warfare!!! Surprise, surprise, no one got hurt!
I just pray that my 2 daughters grow up "normal".