Green Hole is a newly developed village, located on the 6th Floor of the Great Tomb of Nazarick.
Originally, prior to the establishment of the Green Hole, the area it is now situated in used to be part of the verdant forest that covered the majority of the Jungle Floor. However, after Nazarick operatives began to summarily annex the Great Forest of Tob, the area now serves as a new home for many creatures and natives of the New World.
Green Hole is the brainchild of Ainz Ooal Gown, and the very cornerstone of Project Utopia. It is Ainz's intention to use the settlement to accommodate both non-human and human races, so as to form peaceful relationships.
Layout & Features 
The newly created village on the 6th Floor consists of about ten log houses for the immigrated lizardmen. To the right of the village are farming fields and to the left lies an orchard several times the size of the fields. A huge forest surrounds the village and the area where the village is situated looks like a gigantic hole from above, hence the name ‘The Green Hole’. When cutting down trees and digging out their roots, it is inevitable for the ground to be uneven. However, the village is strangely immaculate, organized and clean. This is all thanks to Mare’s magic.
- In the Web Novel, Aura provides an orientation of Nazarick to the villagers in the Green Hole.
- Albedo and majority of the Floor Guardians believe this village is a way to fool and ensnare humans into thinking that Nazarick can coexist with the human realm.
- According to the immigrated dryads and treants, Mare's magic also makes the soil in the area more enriching and fertile than is deemed necessary.
- Due to the relative success of the Green Hole, Ainz wants to use this village as his model of a true utopia for his kingdom.
- In Mass for the Dead, Nazarick cultivated a field of pumpkins on the 6th Floor in what would have been analogous to Green Hole in the Light Novel series.