Leveling a character inWorld of Warcraft: Classicis a balancing act between questing and running dungeons. Questing is good to immerse yourself in an area and get steady EXP. Dungeons are great for getting gear and adding a few levels in a short time. However, not all dungeons are made equal.
If you’re too low-leveled, you risk missing all your attacks and contributing nothing. If you’re too high-leveled, you will receive little or even no experience points from the mobs that populate the world, making it a waste of time. This handy list will help you make sure you’re in the right dungeons based on your level.

Orgrimmar
13-18
The instance portal is in Orgrimmar; may be difficult for Alliance players to run.

15-25
18-23

22-30
Stormwind
The instance portal is in Stormwind; may be difficult for Horde players to run.
24-32
29-38
30-40
26-45
40-50
42-52
44-54
46-55
50-60
52-60
55-60
58-60
58-62
59-63
60-64
60-65
62-65
63-67
64-68
65-69
Terrokar Forest
67-70
Requires key to enter; drops from final boss of Sethekk Halls.
Hellfire Peninsula
68-70
Requires key to enter; questline begins frommob drop in Shadowmoon Valley
The Isle of Quel’Danis
69-70
Added in the Isle of Quel’Danis patch; requires attunement to enter.
The Heroic versions of Burning Crusade dungeons require Level 70 and the necessary reputation to unlock them.
68-72
69-72
72-74
73-75
74-76
75-77
76-78
77-79
79-80
Trial of the Champion
Added in the Icecrown Citadel patch.
The Heroic versions of Wrath of the Lich King dungeons require Level 80 to enter.
Next:Wrath of The Lich King Classic - Death Knight Class Guide