It is situated near the Sabaody Archipelago, and laid directly next to Mariejois on the Red Line. The only safe way to reach Marineford is through the Gates of Justice. However, after the Battle of Marineford, the location of the Marine Headquarters base of operations was exchanged with that of Marine Base G-1.
Marineford is a crescent moon-shaped island that is composed completely of bricks and steel, with cannons on the edges. During the war, Sengoku had the Encircling Wall installed all around Marineford Bay of the island, which is composed of thick and high steel walls that emerge from under the sea, surrounding and trapping anyone who is inside the said area; these walls are composed completely of Wapometal and are resistant to even Whitebeard's shock waves, and has cannons installed in windows at the top, allowing the Marines to barrage the entrapped targets. On the center of the island is an execution scaffold, and around it is a small town with trees around the area. The front of the scaffold, which is a plain and empty area, is known as the Oris Plaza, where the Ox Bell stands at the front.
The majority of the island is occupied by Marineford Town, which is noted to be rather large, especially compared to most other towns and cities in the world. It is mostly home to the families of the Marines stationed at Marineford.
At the back of the island, standing large, tall and proud is the Marine Headquarters building. The building is a large multistory ancient Japanese-stylized palace, with the base bearing the kanji for "Marines" (海軍), with the Marines symbol in between. Around the building's four cardinal corners is a small mountain with a small building on top and a flag with the Marines' symbol placed on top of the roofs each. Two years after the war, the "Marines" kanji has been replaced with "G-1".