Located in the north-west section of the Second Division's grounds, it is surrounded by a thirty ken (approx. 54.54m) wide moat and a high wall. It is accessible by a wooden bridge. On the inside, it resembles a cave, with an area for prisoners.
Treatment for the prisoners is mostly lenient; they can walk freely and converse with one another, but the bleak setting drives many to madness. Prisoners are not held inside a cell and are free to roam the Nest, but they may not set foot outside of the facility. The only exception is the Nest of Maggots' former resident Mayuri Kurotsuchi, who was chained inside a cell.
When a Shinigami becomes a potential danger to other Shinigami and Soul Society, that Shinigami is brought to the Nest of Maggots for imprisonment, regardless if they were put on trial, and even if they did not actually commit any crimes; this is to ensure no danger will be brought to Soul Society. Neither the staff of the Detention Unit nor any other visitors are permitted to carry a Zanpakutō into the Nest of Maggots. This measure means the wardens are required to be able to control the prisoners with bare hands. If a Shinigami desires to enter and is not adept at hand-to-hand combat, they may not enter. This is to prevent rebellions and escapes from the prison.
Kisuke Urahara, as Corps Commander of the Detention Unit, was once in charge of the Nest of Maggots before being promoted to Captain of the 12th Division.