The first half of the Grand Line is known as Paradise. Its name comes from people who have returned from the second half, claiming that the first half is like a paradise in comparison.
The Sabaody Archipelago is the final island in Paradise, close to the Red Line. Though it is called an archipelago, it is actually a massive mangrove forest growing out from the middle of the ocean with each tree of the forest serving as an "island" on which people live. Since it is just a group of trees and not an island like those found in the Grand Line, it has no magnetic pull for which to affect a Log Pose. Due to the place being in close proximity to the part of the Red Line bordering the first half of the Grand Line and the New World, it is a highly visited rest stop for all sorts of travelers to prepare before entering the New World.