Playing at the park- by themselves?

We let our 7 year old play at the park by herself. We have two by our house, one is right behind us (her school) and the other is just down the street. She goes almost every day, but she takes a walkie talkie with her so that we can communicate together. I also let her ride her bike around the block. It might be where we live though, we are in a pretty small, still pretty safe, town.