Udon

Udon is a region located at the southeast of Wano Country currently under the rule of the Beasts Pirates. It is an industrialized region of weapon factories where the lower-class are forced to work to exhaustion and death.

Prisoner Mine
Prisoner Mine (囚人採掘場) is where rebels are tortured until their wills break and they pledge allegiance to Kaido. The Prisoner Mine is divided into six parts: the central fortress and the five labor camps surrounding the the fortress. This layout gives the Prisoner Mine an appearance similar to a blooming flower. Although there are tens of thousands of prisoners currently entombed into the prison, most of them are guilty of rebellion against Kurozumi Orochi, which, in Hyogoro's opinion, was effectively Orochi gathering an army against himself.