Zones
Zones open in a chain: clearing a stage unlocks the next, and a zone's last stage unlocks the next zone. A zone has seven stages, with a mini-boss on stage 4 and the zone boss on stage 7 (Spire Hill Crypt splits its seven across an upper and a lower crypt). On Nightmare and Inferno the same maps return with every enemy at level 70; see difficulties. The same stages are on the world map.
Story zones11
Mini-boss: Raptor · Boss: Bloodmoon WerewolfSpire Hill CryptLevel 11–16 · 4 stagesUnlocks after Kings Woods 7
Mini-boss: Dark Elf MageSpire Hill Crypt LowerLevel 17–19 · 3 stagesUnlocks after Spire Hill Crypt 4
Boss: OgreKings Woods SouthLevel 20–28 · 7 stagesUnlocks after Spire Hill Crypt Lower 3
Mini-boss: Venom Queen · Boss: Ancient Oak TreantTazan WastesLevel 28–34 · 7 stagesUnlocks after Kings Woods South 7
Mini-boss: Sandstorm Harpy Queen · Boss: Dread Sand ManticoreTazan IslesLevel 34–40 · 7 stagesUnlocks after Tazan Wastes 7
Mini-boss: Ancient Shellwarden · Boss: Tidewrath Crab KingThe BarrensLevel 40–46 · 7 stagesUnlocks after Tazan Isles 7
Mini-boss: Serparmat the Devourer · Boss: Redrock LordThe Crimson ValeLevel 46–52 · 7 stagesUnlocks after The Barrens 7
Mini-boss: Goblin Giant · Boss: Lord of the Crimson ValeVeldak HighlandsLevel 52–58 · 7 stagesUnlocks after The Crimson Vale 7
Mini-boss: Ice Hound · Boss: Frost DragonThe Defiled KeepLevel 58–64 · 7 stagesUnlocks after Veldak Highlands 7
Mini-boss: Bone Reaper · Boss: Defiled WyrmThe Cinder CrownLevel 65–70 · 7 stagesUnlocks after The Defiled Keep 7
Mini-boss: Emberfang · Boss: Lord of the CinderTreasure maps3
Dreamy maps are bonus runs that cost a treasure map key for the difficulty you enter on. Keys drop from any wave at a 0.05% chance, from fishing and from the lucky wheel. Each one is a single stage of Dreamwood Drakelings ending in a treasure drake.
Boss: Dreamwood Treasure DrakeDreamy BarrensLevel 46 · unlocks after The Barrens 7Boss: Dreamsand Treasure DrakeDreamy KeepLevel 65 · unlocks after The Defiled Keep 7Boss: Dreamvault Treasure DrakeOther maps
Mythic Rift is the endless endgame map: it needs Inferno, every enemy is level 70, and its tier sets how hard the run is and how much it pays.
Training Grounds holds a training dummy that never dies and never fights back, for testing gear and ability damage. It drops nothing.