These days with everyone suing each other and the Government prosecuting on behalf of 'victims' (even if they don't wish to charge) I am more inclined of leaving it there and walking by.
Good Samaritan deeds are criminal acts. One time I found a lost Casino Rewards Gold Card and was on my way home with it to search through the White Pages (Phone Directory). Police pulled me over randomly in the car on the way home and asked for my ID, the Public Servant noticed the card in my wallet and inquired about it innocently. I replied to the Police Officer that I just found it and am about to do a search for the person in the White Pages. However, I was charged with 'Fraud' (memory tells me also got slapped with Unlawful Property or something), because I did not go straight to the Police Station instead. I asked the Police Officer, what if hypothetically I instead responded I was going straight to the Police Station, would you believe me? The Police Officer said no, and he would of still charged me for Possession of Stolen Property. Went to Court over the matter and pleaded not guilty. Gave my version of the story. Ex-Crown Prosecuting Judge presiding over the case took the Crown Prosecutors's word over mine. Simply put, I was not 'one of them'.
Now, that was many years ago. Good times learning how screwed up the system really is.
/added
Was from that moment I truly started to use my
"Miranda Rights" (common law right). Anything you say 'may be used against you" (not "for you"). Better to keep your mouth shut. In other words; if you do pick up the treasure with good intents and purposes then you are better off not giving it over to the rightful owner. Instead, if you do want to do the right 'thing' call the local Police (Law Enforcers) and notify them immediately - never parting sight with the 'treasure' till a full report is done.