Underworld

The Underworld (アンダーワールド) is the mysterious virtual world in which the Alicization Arc takes place. The Human World is where the Humans live in the Underworld, it's divided into four empires: Norlangarth North Empire, Eastabarieth Empire, Wesdarath Empire, and Southacroith Empire. it's capital is Centoria, from where it's ruled by the Axiom Church and the four empires.

Norlangarth North Empire
Norlangarth North Empire (ノーランガルス北帝国) is the northern empire of the Underworld. Rulid Village is the northernmost village in this empire. Zakkaria is a town to the south of Rulid Village. Deusolbert Synthesis Seven is the Integrity Knight overseeing the Norlangarth Empire.

Eastabarieth Empire
Eastabarieth Empire (イスタバリエス帝国) is the eastern empire of the Underworld.

Wesdarath Empire
Wesdarath Empire (ウェスダラス帝国) is the western empire of the Underworld.

Southacroith Empire
Southacroith Empire (サザークロイス帝国) is the southern empire of the Underworld.

Edge of Human World
Edge of Human World (人界世界の果て) is the border between the Human World and the Dark Territory.

Mountain range at the Edge
The Mountain range at the Edge (果ての山脈) is the mountain range that surrounds the Human World.

Dark Territory
Dark Territory (ダークテリトリー) is the country of demons. It houses goblins, orcs, etc.