There's no reason in taking money to the police if there's no wallet, or something with an ID that goes with the money. I'd stay a few hours at the spot where I found it. Then if no one returned to look for it or claim it, I'd go home with it.
Turn it in, for all you know that just might be all the money someone owns, or money to pay hospitable bills, or donation money for the poor, you just never know, I hope that you would do the right thing too.