I once found a wallet on the sidewalk outside a mall in Japan. I tried to drop it at the mall's lost and found, but the security guard there took me with him to a police box. The policeman there took me to the local police station, and we spent the next hour filling out a report. They were all very friendly and appreciative that I turned it in, but it was really quite an ordeal. If I were to find something valuable again, I might just leave it alone to avoid the hassle.