We all know that there are four road poneglyph which lead to the last island Raftel. And it has been said many times that poneglyph lead to the path of last poneglyph - Rio poneglyph. So the rio poneglyph is ONE PIECE i assume because it is the only object oda can give to luffy beside gold and what i think is this poneglyph reveals the location of three ancient weapons because if you have the power of this three weapons then you can easily conquer/buy the whole world, which is what one piece is famous for!!! What you all think is Rio poneglyph is one piece or not because oda himself confirmed that it is an object not a concept.