Mary Geoise

Mary Geoise is located atop the Red Line at the halfway point of the Grand Line where the Red Line and the Grand Line cross. This is the capital city of the World Government.

Fishman Island

Directly under Mary Geoise at the ocean floor sits Fishman Island, which sits in an underwater passage way that cuts through the red line. This is the most probable way to access the New World.

Reverse Mountain

On the exact opposite side of the world from Mary Geoise is Reverse Mountain, where water from the four Blues flows up the mountain and down into the first half of the Grand Line. The Twin Cape is at the base of the mountain.