I've been thinking about this and it makes me wonder...
Robin mentions only one Poneglyph by name: The Rio Poneglyph that's supposedly on Raftel.
If that Poneglyph has the true history, and the other poneglyphs so far are descriptions of Weapons, is it possible there's a hidden message we're not catching in this?
Let's take the first letter of each location and assign it to the Poneglyph
Rio: Raftel (supposedly)
"A" Poneglyph: Alabasta
"O" Poneglyph: Ohara
"S" Poneglyph: Skypeia.
SOAR is the only word I can make from that. But of course, there's many other Poneglyphs to find out there. Perhaps it's part of a message on how to find the lost kingdom. Oda is a master story-teller, yanno.
Let's add a few letters to our SOAR:
"M" Poneglyph: Marijoi
"E" Poneglyph: Elbaf
"G" Poneglyph: Gyojin Island
Now, let's see.
_REAS___ GO M_______
I'm speculating on the words. But let's pretend I'm right and fill in the blanks:
TREASURE GO MARIJOI
And of course there's millions of other poneglyphs, so:
TO FIND THE REAL TREASURE GO TO MARIJOI
I doubt that's what they say, but...