There was a part in OP ep772, where nami asks Duke about Raftel, and in the end Duke says "Roger had to do it all over again" and nami surprisingly adds "I don't believe it! We r on a journey after the end "
Actually... There is an island where all Log Pose finally point to... its not Raftel
It is when Roger went to this island that he discovered about Raftel and ancient civilisation... he had to start the whole journey over again. (in my opinion this is when he started to read the poneglyphs also)
There are many theories about that last island (the "End") being Elbaf or Wano... :)
I think thats where he found the first road poneglyph and had to start over to find the rest in Order to get to Raftel, because back then theres no telling where or who had them (except big mom apparently had one)