This article lists all core locations (available in all campaigns) by the following tree structure.
Region
A list of all locations in the game, sorted by type can be found under: Locations (by Type)
The Battle Isles[]
Guild Hall
Great Temple of Balthazar
Zaishen Menagerie
Zaishen Challenge
Zaishen Elite
Random Arenas
Codex Arena
Heroes' Ascent (→ Hall of Heroes)