The Holy Land Mariejois is the capital of the World Government and functions as the primary path which individuals seeking to enter the other, far more tumultuous and dangerous side of the Grand Line, the New World, pass through. This route is open only to persons within the jurisdiction of the law or in other words, Marines and World Government agents. This elegant capital furthermore serves as the headquarters of the World Government, the main governing body of the One Piece world. Mariejois' significance and unrivaled importance is also illustrated by the fact that the Reverie meets here on a regular basis in order to discuss current international events and propose and implement solutions.
The gigantic palace is where the Gorosei meet. This palace is seen to have at least six floors, plus extra structures on top, including a number of towers. The palace seem to shrouded in a never ending white mist. The (assumed) main entrance of the palace is guarded by a group of soldiers clad in armor, which is something not seen elsewhere in other government control islands. Its depictions suggest that, due to the high altitude, Mariejois is always foggy. There is also rumors of a "national treasure" the exist somewhere in Mariejois that only the World Nobles know of, and if its existence was revealed to the public, it would throw the world into chaos.