Rio poneglyph?

I had watched all episodes of one piece. But then i took a break so i started all over again, anyways. I just finished all the alabasta episodes (in like 3 days), so i remembered almost everything that happened. Do you guys remember When all of them were in the desert. Zoro, Luffy and chopper get lost and stumble across a poneglyph that is in the middle of nowhere. In a few episodes later somewhere where luffy defeates Crocodile Robin says that it wasn't the poneglyph they were looking for, it was the history of alabasta. and Robin knows that the rio poneglyph has to be in alabasta but then doubts herself. Maybe the poneglyph that luffy zoro and chooper stumbled across was the rio poneglyph???