Skull Dome

The Skull Dome is the main landmark of Onigashima. The castle where Kaido of the Four Emperors lives is built inside of it.

Layout and Locations
The most notable landmark of Onigashima, the Skull Dome is a large rock formation resembling a skull with horns that faces south-east. This mountain is easily visible from a great distance. During the battle atop the Skull Dome, Roronoa Zoro sliced off one of the skull's horns with Enma.

Thanks to its enormous size, the dome's summit can act as a battlefield for numerous fighters, including even Kaido in his gigantic dragon form. The top of the dome can be accessed from Kaido's Castle through a huge set of doors, which allows even the Numbers to go and come as they please.

Most of Onigashima's buildings appear to be directly connected to the Skull Dome, making this landmark central to the Beasts Pirates' operations.

Kaido's Castle


Kaido resides in a towering castle within the Skull Dome, built by Minatomo. It is located at the very rear of the dome, at its northern-most point. The interior resembles a traditional Japanese castle, with sliding doors, paper lanterns and even bonsai tree arrangements. It consists of seven floors in total, specifically five regular ones leading to the dome's summit and two basements, the latter being each split over two further levels.

The castle appears to occupy a considerable portion of the skull's interior and can accommodate even the largest members of the Beasts Pirates with ease. Still, the place is not optimal for fights as during Luffy's battle against two of the Tobiroppo, concern was expressed over the castle's ability to withstand their attacks without suffering serious structural damage. Specific rooms within the castle include a prison cell which was once occupied by Eustass Kid, a room Kaido uses for meetings with his top subordinates. and a room decorated with several bonsai trees and a Japanese armor set.

Second Basement
Somewhere in the second basement lies an underground chamber housing a blue Poneglyph.

Second Floor

 * The Treasure Repository (宝物殿) is where the Nine Red Scabbards rested after their fight against Kaido.

Third Floor

 * The Banquet Hall (宴会場), where Black Maria and many of her direct, yōkai-themed subordinates sought refuge during the Onigashima raid.

Fourth Floor

 * The Nekoka-fé (ネコ科フェ), seemingly run and occupied by Who's-Who and his feline subordinates. Themed after a Cat Café, the large open area features several grossly oversized cat trees.

Rear Entrance


According to the blueprints Kin'emon acquired from Ashura Doji, Kaido's castle has a rear entrance accessible only from the back of the Skull Dome, at the north of Onigashima. There are in fact two entrances, one in an upper level and another in a lower one to its left, both being part of an structure resembling an ancient Japanese shrine on top a rocky staircase. Each entrance is represented with a torii of its own.

Live Floor


The Live Floor (ライブフロア) is where the Golden Kagura celebration takes place. It is located right in front of Kaido's Castle inside the Skull Dome.

It is an enormous banquet hall that can house most of Kaido's forces, including the gigantic Numbers. It has many multi-level towers and private rooms. There is also a DJ station set up here, from where Scratchmen Apoo plays music.

Situated in front of the Live Floor is the Live Stage (ライブステージ), the balcony of Kaido's castle that oversees the banquet hall from above. During the Golden Kagura, Queen held his live performances here.

Woman Trouble
Woman Trouble (女難) is a brothel located to the east of Onigashima. It is owned by Black Maria and directly leads to the insides of the Skull Dome, being a newly added expansion not found in the original blueprints of Kaido's castle. It is built atop a lake and decorated with wisteria shrubs from nearby trees as well as horn-resembling roof protrusions. It directly connects to a long boardwalk that spans from one of the lake's shorelines to the other. During the Golden Kagura, Big Mom stayed here in order to try on a kimono.

According to Big Mom, the building leads into the Live Floor.

Right-Brain Tower
The Right Brain Tower (右脳塔) is a building located west of the Live Floor, connecting it to the outside of the Skull Dome.

After rescuing Kozuki Momonosuke from the Beasts Pirates with Sanji's help, Shinobu fled here with her master while being pursued by a protective Yamato. At the end of the tower's path, Sasaki ambushed Shinobu with his Armored Division and confronted Yamato.

Forehead Floor
The Forehead Floor is the entrance floor of the Skull Dome, located in its southernmost point.

At the end of this floor, there is a set of stairs that leads to the upper Live Floor.

Bathhouse
The Beasts Pirates have a bathhouse located to the west of the Forehead Floor.

It is where Nami and Usopp went after Page One and Ulti decided to give chase to them during the Onigashima raid, with their battle taking place inside.

Storeroom
The storeroom is a room found somewhere within the Skull Dome where discarded objects and junk are kept. Yamato took refuge with Kozuki Momonosuke and Shinobu here once Onigashima took off to the sky.

A destroyed dragon statue is one of the few objects worth of notice found there. It was originally located near the entrance of Onigashima, but was broken by Yamato as a sign of rebellion towards her father. Portgas D. Ace, in a sign of support, melted the statue in order to take responsibility for Yamato's deed and to send a warning to Kaido.