Raftel is the island at the end of the Grand Line which supposedly holds the treasure One Piece.
It is also said that upon reaching Raftel, if one has taken with them along their journey the passages of the Poneglyphs, then the Rio Poneglyph will finally be revealed. Getting to the island is not as simple as sailing to the end of the Grand Line. Oh no there are many obstacles that stand in your way, from dangerous sea-creatures to hazardous weather and everything in between. No one but the legendary Pirate King has made it to Raftel.