A Reverse Shanghai exists in this realm. All the same buildings exist but twisted and landscapes may find themselves inverted.
There are many courts to pass through in Diyu. The First Court is located in Youdu—the capital city of all the hells. Here, their sins on Earth are tallied and then they are sent to their eternal torment. The Final Court lies at the heart of the realm, and was the throne of Yanluo.
Beneath the Final Court lies Avici. It is a wasteland and a workshop of sorts as there is no specific torture designated there. Because it is empty, Yanluo would bring items in and create things in this space to use to torture them one-on-one. Only the worst of sinners are taken to Avici: those who killed an Angel or one's own parent.
The ground and walls are black and featureless, made of no particular material. It is said that it is such a lightless black so that nothing could stain Avici, as "Avici is stain".
For many years, this realm belonged to Yanluo. When Yanluo was killed in 1875, the Portal between this world and Diyu was permanently closed, trapping Baigujing, her daughters, and a number of other demon species.
In 2010, Diyu had been taken over by Sammael, and his warlock minions began opening Portals all across Shanghai for demons to come through. Eventually Alec Lightwood, Magnus Bane, and their friends traveled to Diyu and shut the Portal to their world. Diyu soon began crumbling once Shinyun Jung became a Greater Demon herself and decided to destroy the realm.
- Diyu or 地狱 is the Chinese realm of the dead but the exact number of levels and specific deities in the realm differ in Taoism, Buddhism and the version depicted in The Shadowhunter Chronicles.
- According to Mammon, the Princes of Hell used to throw some big parties in Diyu.