Crimson World

Crimson World (真紅世界 Shinku no Sekai) is an international prison with the purpose of arresting from weak to strong mages, warriors and others. It is located underwater in the middle of the West Ocean

Description
Crimson World is a large submerged tower-like structure whose foundation is at the very bottom of the sea bed. Due to it being built within the West Ocean, the entire structure is constantly surrounded by gigantic ships swimming below the water.

Within the dark confines of the prison are various cells and torture chambers that are used for the prisoners. The cells are all made from seastone to keep those with magical powers from escaping. The torture chambers are used for all sorts of brutal unspeakable acts. Among these include continuous whipping, brutal beating to death, boiling cauldrons for burning and drowning, and spiked pits used for impaling.

The prison is carefully monitored all around by  cameras. Whatever they see is transferred to a larger version that sends video feeds to monitors connected to it, allowing the guards to keep surveillance. Each of the smaller versions has an alarm beeper connected to the shells. The large Surveillance Den Den Mushi is kept in a monitor room somewhere within the fortress.