New World

The New World refers to the second half of the Grand Line. It hasn't been fully explored (save for Gold Roger), and it holds the location of the final island on the Grand Line, Raftel. It is also where the Yonkou, 4 of the strongest pirates in the One Piece world, reside. The New World goes from Mariejoa to the other side of Reverse Mountain. According to Gecko Moria, one will lose everything one cherishes in the New World, something he personally experienced. Also according to him, one shall face what he calls "The Ultimate Nightmare" there, hinting that it is a highly dangerous place.