different things are safe for different children though. The important thing to remember is that they do not know your child or what he is or isn't capable of so you will just need to be sure to be the one who watches your child.
For the record, I don't really care of other people leave their kids unsupervised to roam around huge national parks with all kinds of hazards, if they think their kid is responsible enough to do so (But at 1? Hardly!). I just don't think I am really crazy to believe that someone will WATCH my kid when they say they will.