User blog comment:LordFrz/Why not go the other way/@comment-94.168.119.106-20100924224551

The entrance of the grandline points in only one direction into the first half. Theres no way of surviving the climb over the mountain the other way and I'm sure Oda's already got a solution to that answer anyhow. ITs the same as its not so simple to get into the GL in the first place.