"The Pits" is the local moniker for the lowest level of the Artificial Island. The territory consists of a mechanical room where the island's height is (or was) controlled, and the rest of it was originally intended to be for parking space and storage. The Pits are lit with incandescent lights and halogen lamps, and fluorescent lighting - all of which are powered by noisy generators; the air is pungent with the smell of generator fuel and rotting garbage.
By 2014, the Pits are considered to be some of the most dangerous parts of the island. The Pits are where the most distasteful of deals are made, and where the island's drug addicts and pimps and other unsavory characters congregate. It is very common for people to enter the Pits and never reemerge. Still, people - unsavory, desperate, and otherwise - set up their stands and stalls lined up on narrow roads.
The arrival of Hayato Inui on the Island on August 18, 2014 heralded change for the Pits. He quickly established himself as the 'ruler' of the Pits - and over the next five years, proceeded to clean up the Pits, so to speak. The disappearance rate falls, a few rules are established...gradually, the Pits become safer.
However, Hayato ends up relinquishing control over the Pits after the events of Winter 2019, and he leaves the island (temporarily). In a deal struck by the Western District and the Eastern District, the Pits technically become the Western District's jurisdiction. Without Hayato's influence, and thanks to the Western district's apathy, the Pits devolve back into their lawless state.